diff --git a/src/main/resources/update/gitbucket-core_4.7.xml b/src/main/resources/update/gitbucket-core_4.7.xml
index a128800..4eb2f03 100644
--- a/src/main/resources/update/gitbucket-core_4.7.xml
+++ b/src/main/resources/update/gitbucket-core_4.7.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <changeSet>
     <addColumn tableName="COLLABORATOR">
-        <column name="PERMISSION" type="varchar(10)" nullable="false" defaultValue="ADMIN"/>
+        <column name="ROLE" type="varchar(10)" nullable="false" defaultValue="ADMIN"/>
     </addColumn>
     <addColumn tableName="REPOSITORY">
         <column name="WIKI_OPTION" type="varchar(10)" nullable="false" defaultValue="DISABLE"/>
diff --git a/src/main/scala/gitbucket/core/controller/ApiController.scala b/src/main/scala/gitbucket/core/controller/ApiController.scala
index eddd941..e5229c3 100644
--- a/src/main/scala/gitbucket/core/controller/ApiController.scala
+++ b/src/main/scala/gitbucket/core/controller/ApiController.scala
@@ -524,7 +524,7 @@
   })
 
   private def isEditable(owner: String, repository: String, author: String)(implicit context: Context): Boolean =
-    hasWritePermission(owner, repository, context.loginAccount) || author == context.loginAccount.get.userName
+    hasDeveloperRole(owner, repository, context.loginAccount) || author == context.loginAccount.get.userName
 
 }
 
diff --git a/src/main/scala/gitbucket/core/controller/IssuesController.scala b/src/main/scala/gitbucket/core/controller/IssuesController.scala
index 90aca13..f0afabb 100644
--- a/src/main/scala/gitbucket/core/controller/IssuesController.scala
+++ b/src/main/scala/gitbucket/core/controller/IssuesController.scala
@@ -84,7 +84,7 @@
           getAssignableUserNames(owner, name),
           getMilestones(owner, name),
           getLabels(owner, name),
-          hasWritePermission(owner, name, context.loginAccount),
+          isManageable(repository),
           repository)
       }
     } else Unauthorized()
@@ -386,7 +386,7 @@
    * Tests whether an logged-in user can manage issues.
    */
   private def isManageable(repository: RepositoryInfo)(implicit context: Context): Boolean = {
-    hasWritePermission(repository.owner, repository.name, context.loginAccount)
+    hasDeveloperRole(repository.owner, repository.name, context.loginAccount)
   }
 
   /**
@@ -394,8 +394,9 @@
    */
   private def isEditable(repository: RepositoryInfo)(implicit context: Context): Boolean = {
     repository.repository.options.issuesOption match {
-      case "PUBLIC"  => hasReadPermission(repository.owner, repository.name, context.loginAccount)
-      case "PRIVATE" => hasWritePermission(repository.owner, repository.name, context.loginAccount)
+      case "ALL"     => !repository.repository.isPrivate && context.loginAccount.isDefined
+      case "PUBLIC"  => hasGuestRole(repository.owner, repository.name, context.loginAccount)
+      case "PRIVATE" => hasDeveloperRole(repository.owner, repository.name, context.loginAccount)
       case "DISABLE" => false
     }
   }
@@ -404,7 +405,7 @@
    * Tests whether an issue or a comment is editable by a logged-in user.
    */
   private def isEditableContent(owner: String, repository: String, author: String)(implicit context: Context): Boolean = {
-    hasWritePermission(owner, repository, context.loginAccount) || author == context.loginAccount.get.userName
+    hasDeveloperRole(owner, repository, context.loginAccount) || author == context.loginAccount.get.userName
   }
 
 }
diff --git a/src/main/scala/gitbucket/core/controller/LabelsController.scala b/src/main/scala/gitbucket/core/controller/LabelsController.scala
index ab658eb..08c0aaa 100644
--- a/src/main/scala/gitbucket/core/controller/LabelsController.scala
+++ b/src/main/scala/gitbucket/core/controller/LabelsController.scala
@@ -29,7 +29,7 @@
       getLabels(repository.owner, repository.name),
       countIssueGroupByLabels(repository.owner, repository.name, IssuesService.IssueSearchCondition(), Map.empty),
       repository,
-      hasWritePermission(repository.owner, repository.name, context.loginAccount))
+      hasDeveloperRole(repository.owner, repository.name, context.loginAccount))
   })
 
   ajaxGet("/:owner/:repository/issues/labels/new")(writableUsersOnly { repository =>
@@ -43,7 +43,7 @@
       // TODO futility
       countIssueGroupByLabels(repository.owner, repository.name, IssuesService.IssueSearchCondition(), Map.empty),
       repository,
-      hasWritePermission(repository.owner, repository.name, context.loginAccount))
+      hasDeveloperRole(repository.owner, repository.name, context.loginAccount))
   })
 
   ajaxGet("/:owner/:repository/issues/labels/:labelId/edit")(writableUsersOnly { repository =>
@@ -59,7 +59,7 @@
       // TODO futility
       countIssueGroupByLabels(repository.owner, repository.name, IssuesService.IssueSearchCondition(), Map.empty),
       repository,
-      hasWritePermission(repository.owner, repository.name, context.loginAccount))
+      hasDeveloperRole(repository.owner, repository.name, context.loginAccount))
   })
 
   ajaxPost("/:owner/:repository/issues/labels/:labelId/delete")(writableUsersOnly { repository =>
diff --git a/src/main/scala/gitbucket/core/controller/MilestonesController.scala b/src/main/scala/gitbucket/core/controller/MilestonesController.scala
index f75ea60..de81c73 100644
--- a/src/main/scala/gitbucket/core/controller/MilestonesController.scala
+++ b/src/main/scala/gitbucket/core/controller/MilestonesController.scala
@@ -27,7 +27,7 @@
       params.getOrElse("state", "open"),
       getMilestonesWithIssueCount(repository.owner, repository.name),
       repository,
-      hasWritePermission(repository.owner, repository.name, context.loginAccount))
+      hasDeveloperRole(repository.owner, repository.name, context.loginAccount))
   })
 
   get("/:owner/:repository/issues/milestones/new")(writableUsersOnly {
diff --git a/src/main/scala/gitbucket/core/controller/PullRequestsController.scala b/src/main/scala/gitbucket/core/controller/PullRequestsController.scala
index 548da42..16cef18 100644
--- a/src/main/scala/gitbucket/core/controller/PullRequestsController.scala
+++ b/src/main/scala/gitbucket/core/controller/PullRequestsController.scala
@@ -115,7 +115,7 @@
         val hasConflict = LockUtil.lock(s"${owner}/${name}"){
           checkConflict(owner, name, pullreq.branch, issueId)
         }
-        val hasMergePermission = hasWritePermission(owner, name, context.loginAccount)
+        val hasMergePermission = hasDeveloperRole(owner, name, context.loginAccount)
         val branchProtection = getProtectedBranchInfo(owner, name, pullreq.branch)
         val mergeStatus = PullRequestService.MergeStatus(
            hasConflict         = hasConflict,
@@ -125,7 +125,7 @@
            needStatusCheck     = context.loginAccount.map{ u =>
                                    branchProtection.needStatusCheck(u.userName)
                                  }.getOrElse(true),
-           hasUpdatePermission = hasWritePermission(pullreq.requestUserName, pullreq.requestRepositoryName, context.loginAccount) &&
+           hasUpdatePermission = hasDeveloperRole(pullreq.requestUserName, pullreq.requestRepositoryName, context.loginAccount) &&
                                    context.loginAccount.map{ u =>
                                      !getProtectedBranchInfo(pullreq.requestUserName, pullreq.requestRepositoryName, pullreq.requestBranch).needStatusCheck(u.userName)
                                    }.getOrElse(false),
@@ -163,7 +163,7 @@
       (issue, pullreq) <- getPullRequest(baseRepository.owner, baseRepository.name, issueId)
       owner = pullreq.requestUserName
       name  = pullreq.requestRepositoryName
-      if hasWritePermission(owner, name, context.loginAccount)
+      if hasDeveloperRole(owner, name, context.loginAccount)
     } yield {
       val branchProtection = getProtectedBranchInfo(owner, name, pullreq.requestBranch)
       if(branchProtection.needStatusCheck(loginAccount.userName)){
@@ -374,7 +374,7 @@
               forkedRepository,
               originRepository,
               forkedRepository,
-              hasWritePermission(originRepository.owner, originRepository.name, context.loginAccount),
+              hasDeveloperRole(originRepository.owner, originRepository.name, context.loginAccount),
               getAssignableUserNames(originRepository.owner, originRepository.name),
               getMilestones(originRepository.owner, originRepository.name),
               getLabels(originRepository.owner, originRepository.name)
@@ -389,7 +389,7 @@
     }) getOrElse NotFound()
   })
 
-  ajaxGet("/:owner/:repository/compare/*...*/mergecheck")(writableUsersOnly { forkedRepository =>
+  ajaxGet("/:owner/:repository/compare/*...*/mergecheck")(readableUsersOnly { forkedRepository =>
     val Seq(origin, forked) = multiParams("splat")
     val (originOwner, tmpOriginBranch) = parseCompareIdentifie(origin, forkedRepository.owner)
     val (forkedOwner, tmpForkedBranch) = parseCompareIdentifie(forked, forkedRepository.owner)
@@ -544,7 +544,7 @@
    * Tests whether an logged-in user can manage pull requests.
    */
   private def isManageable(repository: RepositoryInfo)(implicit context: Context): Boolean = {
-    hasWritePermission(repository.owner, repository.name, context.loginAccount)
+    hasDeveloperRole(repository.owner, repository.name, context.loginAccount)
   }
 
   /**
@@ -552,8 +552,9 @@
    */
   private def isEditable(repository: RepositoryInfo)(implicit context: Context): Boolean = {
     repository.repository.options.issuesOption match {
-      case "PUBLIC"  => hasReadPermission(repository.owner, repository.name, context.loginAccount)
-      case "PRIVATE" => hasWritePermission(repository.owner, repository.name, context.loginAccount)
+      case "ALL"     => !repository.repository.isPrivate && context.loginAccount.isDefined
+      case "PUBLIC"  => hasGuestRole(repository.owner, repository.name, context.loginAccount)
+      case "PRIVATE" => hasDeveloperRole(repository.owner, repository.name, context.loginAccount)
       case "DISABLE" => false
     }
   }
diff --git a/src/main/scala/gitbucket/core/controller/RepositorySettingsController.scala b/src/main/scala/gitbucket/core/controller/RepositorySettingsController.scala
index f9ea3d0..be35a20 100644
--- a/src/main/scala/gitbucket/core/controller/RepositorySettingsController.scala
+++ b/src/main/scala/gitbucket/core/controller/RepositorySettingsController.scala
@@ -179,8 +179,8 @@
     val collaborators = params("collaborators")
     removeCollaborators(repository.owner, repository.name)
     collaborators.split(",").withFilter(_.nonEmpty).map { collaborator =>
-      val userName :: permission :: Nil = collaborator.split(":").toList
-      addCollaborator(repository.owner, repository.name, userName, permission)
+      val userName :: role :: Nil = collaborator.split(":").toList
+      addCollaborator(repository.owner, repository.name, userName, role)
     }
     redirect(s"/${repository.owner}/${repository.name}/settings/collaborators")
   })
@@ -416,7 +416,7 @@
    */
   private def featureOption: Constraint = new Constraint(){
     override def validate(name: String, value: String, params: Map[String, String], messages: Messages): Option[String] =
-      if(Seq("DISABLE", "PRIVATE", "PUBLIC").contains(value)) None else Some("Option is invalid.")
+      if(Seq("DISABLE", "PRIVATE", "PUBLIC", "ALL").contains(value)) None else Some("Option is invalid.")
   }
 
 
diff --git a/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala b/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala
index ad8b091..92f9bbf 100644
--- a/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala
+++ b/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala
@@ -110,7 +110,7 @@
       enableLineBreaks = params("enableLineBreaks").toBoolean,
       enableTaskList = params("enableTaskList").toBoolean,
       enableAnchor = false,
-      hasWritePermission = hasWritePermission(repository.owner, repository.name, context.loginAccount)
+      hasWritePermission = hasDeveloperRole(repository.owner, repository.name, context.loginAccount)
     )
   })
 
@@ -151,7 +151,7 @@
           html.commits(if(path.isEmpty) Nil else path.split("/").toList, branchName, repository,
             logs.splitWith{ (commit1, commit2) =>
               view.helpers.date(commit1.commitTime) == view.helpers.date(commit2.commitTime)
-            }, page, hasNext, hasWritePermission(repository.owner, repository.name, context.loginAccount))
+            }, page, hasNext, hasDeveloperRole(repository.owner, repository.name, context.loginAccount))
         case Left(_) => NotFound()
       }
     }
@@ -275,7 +275,7 @@
           html.blob(id, repository, path.split("/").toList,
             JGitUtil.getContentInfo(git, path, objectId),
             new JGitUtil.CommitInfo(JGitUtil.getLastModifiedCommit(git, revCommit, path)),
-            hasWritePermission(repository.owner, repository.name, context.loginAccount),
+            hasDeveloperRole(repository.owner, repository.name, context.loginAccount),
             request.paths(2) == "blame")
         }
       } getOrElse NotFound()
@@ -329,7 +329,7 @@
                 JGitUtil.getBranchesOfCommit(git, revCommit.getName),
                 JGitUtil.getTagsOfCommit(git, revCommit.getName),
                 getCommitComments(repository.owner, repository.name, id, false),
-                repository, diffs, oldCommitId, hasWritePermission(repository.owner, repository.name, context.loginAccount))
+                repository, diffs, oldCommitId, hasDeveloperRole(repository.owner, repository.name, context.loginAccount))
           }
         }
       }
@@ -358,7 +358,7 @@
     html.commentform(
       commitId = id,
       fileName, oldLineNumber, newLineNumber, issueId,
-      hasWritePermission = hasWritePermission(repository.owner, repository.name, context.loginAccount),
+      hasWritePermission = hasDeveloperRole(repository.owner, repository.name, context.loginAccount),
       repository = repository
     )
   })
@@ -374,7 +374,7 @@
         callPullRequestReviewCommentWebHook("create", comment, repository, issueId, context.baseUrl, context.loginAccount.get)
       case None => recordCommentCommitActivity(repository.owner, repository.name, context.loginAccount.get.userName, id, form.content)
     }
-    helper.html.commitcomment(comment, hasWritePermission(repository.owner, repository.name, context.loginAccount), repository)
+    helper.html.commitcomment(comment, hasDeveloperRole(repository.owner, repository.name, context.loginAccount), repository)
   })
 
   ajaxGet("/:owner/:repository/commit_comments/_data/:id")(readableUsersOnly { repository =>
@@ -393,7 +393,7 @@
                 enableRefsLink = true,
                 enableAnchor = true,
                 enableLineBreaks = true,
-                hasWritePermission = isEditable(x.userName, x.repositoryName, x.commentedUserName)
+                hasWritePermission = true
               )
             ))
         }
@@ -437,7 +437,7 @@
     .map(br => (br, getPullRequestByRequestCommit(repository.owner, repository.name, repository.repository.defaultBranch, br.name, br.commitId), protectedBranches.contains(br.name)))
     .reverse
 
-    html.branches(branches, hasWritePermission(repository.owner, repository.name, context.loginAccount), repository)
+    html.branches(branches, hasDeveloperRole(repository.owner, repository.name, context.loginAccount), repository)
   })
 
   /**
@@ -547,7 +547,7 @@
    */
   private def fileList(repository: RepositoryService.RepositoryInfo, revstr: String = "", path: String = ".") = {
     if(repository.commitCount == 0){
-      html.guide(repository, hasWritePermission(repository.owner, repository.name, context.loginAccount))
+      html.guide(repository, hasDeveloperRole(repository.owner, repository.name, context.loginAccount))
     } else {
       using(Git.open(getRepositoryDir(repository.owner, repository.name))){ git =>
         // get specified commit
@@ -569,7 +569,7 @@
             html.files(revision, repository,
               if(path == ".") Nil else path.split("/").toList, // current path
               new JGitUtil.CommitInfo(lastModifiedCommit), // last modified commit
-              files, readme, hasWritePermission(repository.owner, repository.name, context.loginAccount),
+              files, readme, hasDeveloperRole(repository.owner, repository.name, context.loginAccount),
               getPullRequestFromBranch(repository.owner, repository.name, revstr, repository.repository.defaultBranch),
               flash.get("info"), flash.get("error"))
           }
@@ -691,7 +691,7 @@
   }
 
   private def isEditable(owner: String, repository: String, author: String)(implicit context: Context): Boolean =
-    hasWritePermission(owner, repository, context.loginAccount) || author == context.loginAccount.get.userName
+    hasDeveloperRole(owner, repository, context.loginAccount) || author == context.loginAccount.get.userName
 
   override protected def renderUncaughtException(e: Throwable)(implicit request: HttpServletRequest, response: HttpServletResponse): Unit = {
     e.printStackTrace()
diff --git a/src/main/scala/gitbucket/core/controller/WikiController.scala b/src/main/scala/gitbucket/core/controller/WikiController.scala
index 64d0b27..f46b4be 100644
--- a/src/main/scala/gitbucket/core/controller/WikiController.scala
+++ b/src/main/scala/gitbucket/core/controller/WikiController.scala
@@ -242,9 +242,9 @@
 
   private def isEditable(repository: RepositoryInfo)(implicit context: Context): Boolean = {
     repository.repository.options.wikiOption match {
-//      case "ALL"     => repository.repository.isPrivate == false || hasReadPermission(repository.owner, repository.name, context.loginAccount)
-      case "PUBLIC"  => hasReadPermission(repository.owner, repository.name, context.loginAccount)
-      case "PRIVATE" => hasWritePermission(repository.owner, repository.name, context.loginAccount)
+      case "ALL"     => !repository.repository.isPrivate && context.loginAccount.isDefined
+      case "PUBLIC"  => hasGuestRole(repository.owner, repository.name, context.loginAccount)
+      case "PRIVATE" => hasDeveloperRole(repository.owner, repository.name, context.loginAccount)
       case "DISABLE" => false
     }
   }
diff --git a/src/main/scala/gitbucket/core/model/Collaborator.scala b/src/main/scala/gitbucket/core/model/Collaborator.scala
index 5036e3a..c810613 100644
--- a/src/main/scala/gitbucket/core/model/Collaborator.scala
+++ b/src/main/scala/gitbucket/core/model/Collaborator.scala
@@ -7,8 +7,8 @@
 
   class Collaborators(tag: Tag) extends Table[Collaborator](tag, "COLLABORATOR") with BasicTemplate {
     val collaboratorName = column[String]("COLLABORATOR_NAME")
-    val permission = column[String]("PERMISSION")
-    def * = (userName, repositoryName, collaboratorName, permission) <> (Collaborator.tupled, Collaborator.unapply)
+    val role = column[String]("ROLE")
+    def * = (userName, repositoryName, collaboratorName, role) <> (Collaborator.tupled, Collaborator.unapply)
 
     def byPrimaryKey(owner: String, repository: String, collaborator: String) =
       byRepository(owner, repository) && (collaboratorName === collaborator.bind)
@@ -19,15 +19,15 @@
   userName: String,
   repositoryName: String,
   collaboratorName: String,
-  permission: String
+  role: String
 )
 
-sealed abstract class Permission(val name: String)
+sealed abstract class Role(val name: String)
 
-object Permission {
-  object ADMIN extends Permission("ADMIN")
-  object WRITE extends Permission("WRITE")
-  object READ  extends Permission("READ")
+object Role {
+  object ADMIN extends Role("ADMIN")
+  object DEVELOPER extends Role("DEVELOPER")
+  object GUEST extends Role("GUEST")
 
 //  val values: Vector[Permission] = Vector(ADMIN, WRITE, READ)
 //
diff --git a/src/main/scala/gitbucket/core/service/IssuesService.scala b/src/main/scala/gitbucket/core/service/IssuesService.scala
index e604e0b..c050e79 100644
--- a/src/main/scala/gitbucket/core/service/IssuesService.scala
+++ b/src/main/scala/gitbucket/core/service/IssuesService.scala
@@ -434,7 +434,7 @@
   }
 
   def getAssignableUserNames(owner: String, repository: String)(implicit s: Session): List[String] = {
-    (getCollaboratorUserNames(owner, repository, Seq(Permission.ADMIN, Permission.WRITE)) :::
+    (getCollaboratorUserNames(owner, repository, Seq(Role.ADMIN, Role.DEVELOPER)) :::
       (if (getAccountByUserName(owner).get.isGroupAccount) getGroupMembers(owner).map(_.userName) else List(owner))).distinct.sorted
   }
 
diff --git a/src/main/scala/gitbucket/core/service/RepositoryService.scala b/src/main/scala/gitbucket/core/service/RepositoryService.scala
index 26fa159..11d6ba6 100644
--- a/src/main/scala/gitbucket/core/service/RepositoryService.scala
+++ b/src/main/scala/gitbucket/core/service/RepositoryService.scala
@@ -1,7 +1,7 @@
 package gitbucket.core.service
 
 import gitbucket.core.controller.Context
-import gitbucket.core.model.{Collaborator, Repository, RepositoryOptions, Account, Permission}
+import gitbucket.core.model.{Collaborator, Repository, RepositoryOptions, Account, Role}
 import gitbucket.core.model.Profile._
 import gitbucket.core.util.JGitUtil
 import profile.simple._
@@ -335,8 +335,8 @@
   /**
    * Add collaborator (user or group) to the repository.
    */
-  def addCollaborator(userName: String, repositoryName: String, collaboratorName: String, permission: String)(implicit s: Session): Unit =
-    Collaborators insert Collaborator(userName, repositoryName, collaboratorName, permission)
+  def addCollaborator(userName: String, repositoryName: String, collaboratorName: String, role: String)(implicit s: Session): Unit =
+    Collaborators insert Collaborator(userName, repositoryName, collaboratorName, role)
 
   /**
    * Remove all collaborators from the repository.
@@ -359,38 +359,38 @@
    * Returns the list of all collaborator name and permission which is sorted with ascending order.
    * If a group is added as a collaborator, this method returns users who are belong to that group.
    */
-  def getCollaboratorUserNames(userName: String, repositoryName: String, filter: Seq[Permission] = Nil)(implicit s: Session): List[String] = {
+  def getCollaboratorUserNames(userName: String, repositoryName: String, filter: Seq[Role] = Nil)(implicit s: Session): List[String] = {
     val q1 = Collaborators
       .innerJoin(Accounts).on { case (t1, t2) => (t1.collaboratorName === t2.userName) && (t2.groupAccount === false.bind) }
       .filter { case (t1, t2) => t1.byRepository(userName, repositoryName) }
-      .map { case (t1, t2) => (t1.collaboratorName, t1.permission) }
+      .map { case (t1, t2) => (t1.collaboratorName, t1.role) }
 
     val q2 = Collaborators
       .innerJoin(Accounts).on { case (t1, t2) => (t1.collaboratorName === t2.userName) && (t2.groupAccount === true.bind) }
       .innerJoin(GroupMembers).on { case ((t1, t2), t3) => t2.userName === t3.groupName }
       .filter { case ((t1, t2), t3) => t1.byRepository(userName, repositoryName) }
-      .map { case ((t1, t2), t3) => (t3.userName, t1.permission) }
+      .map { case ((t1, t2), t3) => (t3.userName, t1.role) }
 
     q1.union(q2).list.filter { x => filter.isEmpty || filter.exists(_.name == x._2) }.map(_._1)
   }
 
 
-  def hasWritePermission(owner: String, repository: String, loginAccount: Option[Account])(implicit s: Session): Boolean = {
+  def hasDeveloperRole(owner: String, repository: String, loginAccount: Option[Account])(implicit s: Session): Boolean = {
     loginAccount match {
       case Some(a) if(a.isAdmin) => true
       case Some(a) if(a.userName == owner) => true
       case Some(a) if(getGroupMembers(owner).exists(_.userName == a.userName)) => true
-      case Some(a) if(getCollaboratorUserNames(owner, repository, Seq(Permission.ADMIN, Permission.WRITE)).contains(a.userName)) => true
+      case Some(a) if(getCollaboratorUserNames(owner, repository, Seq(Role.ADMIN, Role.DEVELOPER)).contains(a.userName)) => true
       case _ => false
     }
   }
 
-  def hasReadPermission(owner: String, repository: String, loginAccount: Option[Account])(implicit s: Session): Boolean = {
+  def hasGuestRole(owner: String, repository: String, loginAccount: Option[Account])(implicit s: Session): Boolean = {
     loginAccount match {
       case Some(a) if(a.isAdmin) => true
       case Some(a) if(a.userName == owner) => true
       case Some(a) if(getGroupMembers(owner).exists(_.userName == a.userName)) => true
-      case Some(a) if(getCollaboratorUserNames(owner, repository, Seq(Permission.ADMIN, Permission.WRITE, Permission.READ)).contains(a.userName)) => true
+      case Some(a) if(getCollaboratorUserNames(owner, repository, Seq(Role.ADMIN, Role.DEVELOPER, Role.GUEST)).contains(a.userName)) => true
       case _ => false
     }
   }
diff --git a/src/main/scala/gitbucket/core/servlet/GitAuthenticationFilter.scala b/src/main/scala/gitbucket/core/servlet/GitAuthenticationFilter.scala
index c079eb8..d0b92bd 100644
--- a/src/main/scala/gitbucket/core/servlet/GitAuthenticationFilter.scala
+++ b/src/main/scala/gitbucket/core/servlet/GitAuthenticationFilter.scala
@@ -84,7 +84,7 @@
                 Array(username, password) = AuthUtil.decodeAuthHeader(auth).split(":", 2)
                 account <- authenticate(settings, username, password)
               } yield if(isUpdating || repository.repository.isPrivate){
-                  if(hasWritePermission(repository.owner, repository.name, Some(account))){
+                  if(hasDeveloperRole(repository.owner, repository.name, Some(account))){
                     request.setAttribute(Keys.Request.UserName, account.userName)
                     true
                   } else false
diff --git a/src/main/scala/gitbucket/core/ssh/GitCommand.scala b/src/main/scala/gitbucket/core/ssh/GitCommand.scala
index f1ebb09..6e374b9 100644
--- a/src/main/scala/gitbucket/core/ssh/GitCommand.scala
+++ b/src/main/scala/gitbucket/core/ssh/GitCommand.scala
@@ -92,7 +92,7 @@
   protected def isWritableUser(username: String, repositoryInfo: RepositoryService.RepositoryInfo)
                               (implicit session: Session): Boolean =
     getAccountByUserName(username) match {
-      case Some(account) => hasWritePermission(repositoryInfo.owner, repositoryInfo.name, Some(account))
+      case Some(account) => hasDeveloperRole(repositoryInfo.owner, repositoryInfo.name, Some(account))
       case None => false
     }
 
diff --git a/src/main/scala/gitbucket/core/util/Authenticator.scala b/src/main/scala/gitbucket/core/util/Authenticator.scala
index b4cfef5..bbcb339 100644
--- a/src/main/scala/gitbucket/core/util/Authenticator.scala
+++ b/src/main/scala/gitbucket/core/util/Authenticator.scala
@@ -2,13 +2,11 @@
 
 import gitbucket.core.controller.ControllerBase
 import gitbucket.core.service.{AccountService, RepositoryService}
-import gitbucket.core.model.Permission
+import gitbucket.core.model.Role
 import RepositoryService.RepositoryInfo
 import Implicits._
 import ControlUtil._
 
-import scala.collection.Searching.search
-
 /**
  * Allows only oneself and administrators.
  */
@@ -45,7 +43,7 @@
             case Some(x) if(repository.owner == x.userName) => action(repository)
             // TODO Repository management is allowed for only group managers?
             case Some(x) if(getGroupMembers(repository.owner).exists { m => m.userName == x.userName && m.isManager == true }) => action(repository)
-            case Some(x) if(getCollaboratorUserNames(paths(0), paths(1), Seq(Permission.ADMIN)).contains(x.userName)) => action(repository)
+            case Some(x) if(getCollaboratorUserNames(paths(0), paths(1), Seq(Role.ADMIN)).contains(x.userName)) => action(repository)
             case _ => Unauthorized()
           }
         } getOrElse NotFound()
@@ -156,7 +154,7 @@
             case Some(x) if(x.isAdmin) => action(repository)
             case Some(x) if(paths(0) == x.userName) => action(repository)
             case Some(x) if(getGroupMembers(repository.owner).exists(_.userName == x.userName)) => action(repository)
-            case Some(x) if(getCollaboratorUserNames(paths(0), paths(1), Seq(Permission.ADMIN, Permission.WRITE)).contains(x.userName)) => action(repository)
+            case Some(x) if(getCollaboratorUserNames(paths(0), paths(1), Seq(Role.ADMIN, Role.DEVELOPER)).contains(x.userName)) => action(repository)
             case _ => Unauthorized()
           }
         } getOrElse NotFound()
diff --git a/src/main/twirl/gitbucket/core/settings/collaborators.scala.html b/src/main/twirl/gitbucket/core/settings/collaborators.scala.html
index 3aeb44d..70487da 100644
--- a/src/main/twirl/gitbucket/core/settings/collaborators.scala.html
+++ b/src/main/twirl/gitbucket/core/settings/collaborators.scala.html
@@ -2,7 +2,7 @@
   isGroupRepository: Boolean,
   repository: gitbucket.core.service.RepositoryService.RepositoryInfo)(implicit context: gitbucket.core.controller.Context)
 @import gitbucket.core.view.helpers
-@import gitbucket.core.model.Permission
+@import gitbucket.core.model.Role
 @gitbucket.core.html.main("Settings", Some(repository)){
   @gitbucket.core.html.menu("settings", repository){
     @gitbucket.core.settings.html.menu("collaborators", repository){
@@ -77,7 +77,8 @@
     $.post('@context.path/_user/existence', { 'userName': userName },
       function(data, status){
         if(data != ''){
-          addListHTML(userName, '@Permission.ADMIN.name', '#' + id + '-list');
+          addListHTML(userName, '@Role.ADMIN.name', '#' + id + '-list');
+          $('#userName-' + id).val('');
         } else {
           $('#error-' + id).text('User does not exist.');
         }
@@ -94,26 +95,26 @@
   });
 
   @collaborators.map { case (collaborator, isGroup) =>
-    addListHTML('@collaborator.collaboratorName', '@collaborator.permission', @if(isGroup){'#group-list'}else{'#collaborator-list'});
+    addListHTML('@collaborator.collaboratorName', '@collaborator.role', @if(isGroup){'#group-list'}else{'#collaborator-list'});
   }
 
-  function addListHTML(userName, permission, id){
-    var adminButton = $('<label class="btn btn-default btn-mini"><input type="radio" value="@Permission.ADMIN.name" name="' + userName + '">Admin</label>');
-    if(permission == '@Permission.ADMIN.name'){
+  function addListHTML(userName, role, id){
+    var adminButton = $('<label class="btn btn-default btn-mini"><input type="radio" value="@Role.ADMIN.name" name="' + userName + '">Admin</label>');
+    if(role == '@Role.ADMIN.name'){
       adminButton.addClass('active');
     }
-    var writeButton = $('<label class="btn btn-default btn-mini"><input type="radio" value="@Permission.WRITE.name" name="' + userName + '">Write</label>');
-    if(permission == '@Permission.WRITE.name'){
+    var writeButton = $('<label class="btn btn-default btn-mini"><input type="radio" value="@Role.DEVELOPER.name" name="' + userName + '">Developer</label>');
+    if(role == '@Role.DEVELOPER.name'){
       writeButton.addClass('active');
     }
-    var readButton = $('<label class="btn btn-default btn-mini"><input type="radio" value="@Permission.READ.name" name="' + userName + '">Read</label>');
-    if(permission == '@Permission.READ.name'){
+    var readButton = $('<label class="btn btn-default btn-mini"><input type="radio" value="@Role.GUEST.name" name="' + userName + '">Guest</label>');
+    if(role == '@Role.GUEST.name'){
       readButton.addClass('active');
     }
 
     $(id).append($('<li>')
       .data('name', userName)
-      .append($('<div class="btn-group permission" data-toggle="buttons">')
+      .append($('<div class="btn-group role" data-toggle="buttons">')
         .append(adminButton)
         .append(writeButton)
         .append(readButton))
diff --git a/src/main/twirl/gitbucket/core/settings/options.scala.html b/src/main/twirl/gitbucket/core/settings/options.scala.html
index f978b58..835c14d 100644
--- a/src/main/twirl/gitbucket/core/settings/options.scala.html
+++ b/src/main/twirl/gitbucket/core/settings/options.scala.html
@@ -61,12 +61,17 @@
               </div>
               <div class="radio">
                 <label>
-                  <input type="radio" name="issuesOption" value="PRIVATE" @if(repository.repository.options.issuesOption == "PRIVATE"){ checked}> Writable users can view, create and comment on issues
+                  <input type="radio" name="issuesOption" value="PRIVATE" @if(repository.repository.options.issuesOption == "PRIVATE"){ checked}> Developers can view, create and comment on issues
                 </label>
               </div>
               <div class="radio">
                 <label>
-                  <input type="radio" name="issuesOption" value="PUBLIC" @if(repository.repository.options.issuesOption == "PUBLIC"){ checked}> Readable users can view, create and comment on isues
+                  <input type="radio" name="issuesOption" value="PUBLIC" @if(repository.repository.options.issuesOption == "PUBLIC"){ checked}> Developers and guests can view, create and comment on isues
+                </label>
+              </div>
+              <div class="radio for-public-repo">
+                <label>
+                  <input type="radio" name="issuesOption" value="ALL" @if(repository.repository.options.issuesOption == "ALL"){ checked}> All users can view, create and comment on isues
                 </label>
               </div>
               <label for="externalIssuesUrl" class="strong">External URL:
@@ -87,12 +92,17 @@
               </div>
               <div class="radio">
                 <label>
-                  <input type="radio" name="wikiOption" value="PRIVATE" @if(repository.repository.options.wikiOption == "PRIVATE"){ checked}> Writable users can view, create and edit wiki pages
+                  <input type="radio" name="wikiOption" value="PRIVATE" @if(repository.repository.options.wikiOption == "PRIVATE"){ checked}> Developers can view, create and edit wiki pages
                 </label>
               </div>
               <div class="radio">
                 <label>
-                  <input type="radio" name="wikiOption" value="PUBLIC" @if(repository.repository.options.wikiOption == "PUBLIC"){ checked}> Readable users can view, create and edit wiki pages
+                  <input type="radio" name="wikiOption" value="PUBLIC" @if(repository.repository.options.wikiOption == "PUBLIC"){ checked}> Developers ans guests can view, create and edit wiki pages
+                </label>
+              </div>
+              <div class="radio for-public-repo">
+                <label>
+                  <input type="radio" name="wikiOption" value="ALL" @if(repository.repository.options.issuesOption == "ALL"){ checked}> All users can view, create and comment on isues
                 </label>
               </div>
               <label for="externalWikiUrl" class="strong">External URL:
@@ -112,14 +122,25 @@
 <script>
 $(function(){
   updateFeatures();
-
-  $('input[name=issuesOption], input[name=wikiOption]').click(function(){
+  $('input[name=isPrivate], input[name=issuesOption], input[name=wikiOption]').click(function(){
     updateFeatures();
   });
 });
 
 function updateFeatures() {
-  $('#externalIssuesUrl').prop('disabled', !$('input[name=issuesOption]').select('[value=DISABLE]').prop('checked'));
-  $('#externalWikiUrl').prop('disabled', !$('input[name=wikiOption]').select('[value=DISABLE]').prop('checked'));
+  if($('input[name=isPrivate]:checked').val() == 'false'){
+    $('.for-public-repo').show();
+  } else {
+    if($('input[name=issuesOption]:checked').val() == 'ALL'){
+      $('input[name=issuesOption][value=PUBLIC]').prop('checked', true);
+    }
+    if($('input[name=wikiOption]:checked').val() == 'ALL'){
+      $('input[name=wikiOption][value=PUBLIC]').prop('checked', true);
+    }
+    $('.for-public-repo').hide();
+  }
+
+  $('#externalIssuesUrl').prop('disabled', $('input[name=issuesOption]:checked').val() != 'DISABLE');
+  $('#externalWikiUrl').prop('disabled', $('input[name=wikiOption]:checked').val() != 'DISABLE');
 }
 </script>