diff -rN -u old-smederee/modules/darcs/src/main/scala/de/smederee/darcs/DarcsCommands.scala new-smederee/modules/darcs/src/main/scala/de/smederee/darcs/DarcsCommands.scala
--- old-smederee/modules/darcs/src/main/scala/de/smederee/darcs/DarcsCommands.scala	2025-02-02 09:48:36.768627283 +0000
+++ new-smederee/modules/darcs/src/main/scala/de/smederee/darcs/DarcsCommands.scala	2025-02-02 09:48:36.772627289 +0000
@@ -73,6 +73,31 @@
 final class DarcsCommands[F[_]: Sync](val darcsBinary: Path) {
   private val log = LoggerFactory.getLogger(getClass)
 
+  /** Clone a darcs repository from one directory into another one. This function is intended to be used for
+    * server side forking or repositories.
+    *
+    * @param sourceRepositoryPath
+    *   The path of the source repository.
+    * @param targetRespositoryPath
+    *   The path of the target repository.
+    * @param options
+    *   Additional options for the clone command.
+    * @return
+    *   The output of the darcs command.
+    */
+  def clone(sourceRepositoryPath: Path, targetRespositoryPath: Path)(
+      options: Chain[String]
+  ): F[DarcsCommandOutput] = {
+    val source = sourceRepositoryPath.toAbsolutePath
+    val target = targetRespositoryPath.toAbsolutePath
+    log.trace(s"Execute $darcsBinary clone $sourceRepositoryPath to $targetRespositoryPath with $options")
+    val darcsOptions    = List("clone") ::: options.toList ::: List(source.toString, target.toString)
+    val externalCommand = os.proc(darcsBinary.toString, darcsOptions)
+    for {
+      process <- Sync[F].delay(externalCommand.call(check = false))
+    } yield DarcsCommandOutput(process.exitCode, Chain(process.out.text()), Chain(process.err.text()))
+  }
+
   /** Initialize a darcs repository under the given base path with the provided name. This is done by running
     * the external darcs binary with the appropriate parameters.
     *
diff -rN -u old-smederee/modules/darcs/src/test/scala/de/smederee/darcs/DarcsCommandsTest.scala new-smederee/modules/darcs/src/test/scala/de/smederee/darcs/DarcsCommandsTest.scala
--- old-smederee/modules/darcs/src/test/scala/de/smederee/darcs/DarcsCommandsTest.scala	2025-02-02 09:48:36.768627283 +0000
+++ new-smederee/modules/darcs/src/test/scala/de/smederee/darcs/DarcsCommandsTest.scala	2025-02-02 09:48:36.772627289 +0000
@@ -37,6 +37,39 @@
 
   override def munitFixtures = List(workingDirectory)
 
+  test("darcs clone must create a proper copy") {
+    val cmd    = new DarcsCommands[IO](darcsBinary)
+    val source = Paths.get(workingDirectory().toString, "source")
+    val target = Paths.get(workingDirectory().toString, "target")
+    val test =
+      for {
+        init  <- cmd.initialize(workingDirectory())("source")(Chain.empty)
+        clone <- cmd.clone(source, target)(Chain.empty)
+      } yield (init, clone)
+    test.map { output =>
+      val (init, clone) = output
+      assert(init.exitValue === 0, "darcs init did not finish with exit code 0!")
+      assert(Files.exists(source.toAbsolutePath), "Source repository directory does not exist!")
+      assert(clone.exitValue === 0, "darcs clone did not finish with exit code 0!")
+      assert(Files.exists(target.toAbsolutePath), "Target repository directory does not exist!")
+    }
+  }
+
+  test("darcs clone must fail if the source does not exist") {
+    val cmd    = new DarcsCommands[IO](darcsBinary)
+    val source = Paths.get(workingDirectory().toString, "source-should-not-exist")
+    val target = Paths.get(workingDirectory().toString, "target-should-not-be-created")
+    val test =
+      for {
+        clone <- cmd.clone(source, target)(Chain.empty)
+      } yield clone
+    test.map { clone =>
+      assert(!Files.exists(source.toAbsolutePath), "Source repository directory must not exist!")
+      assert(clone.exitValue =!= 0, "darcs clone must not finish with exit code 0!")
+      assert(!Files.exists(target.toAbsolutePath), "Target repository directory must not exist!")
+    }
+  }
+
   test("darcs initialize must create a new repository") {
     val cmd               = new DarcsCommands[IO](darcsBinary)
     val repo              = "test-repository"
diff -rN -u old-smederee/modules/hub/src/main/resources/messages_en.properties new-smederee/modules/hub/src/main/resources/messages_en.properties
--- old-smederee/modules/hub/src/main/resources/messages_en.properties	2025-02-02 09:48:36.768627283 +0000
+++ new-smederee/modules/hub/src/main/resources/messages_en.properties	2025-02-02 09:48:36.772627289 +0000
@@ -25,6 +25,7 @@
 form.create-repo.website=Website
 form.create-repo.website.placeholder=https://example.com
 form.create-repo.website.help=An optional URI pointing to the website of your project.
+form.fork.button.submit=Clone to your account.
 form.login.button.submit=Login
 form.login.password=Password
 form.login.password.placeholder=Please enter your password here.
@@ -130,6 +131,7 @@
 repository.menu.website.tooltip=Click here to open the project website ({0}) in a new tab or window.
 repository.description.title=Summary:
 
+repository.overview.clone.fork=Create your personal fork.
 repository.overview.clone.title=Clone this repository
 repository.overview.clone.read-only=read-only
 repository.overview.clone.read-write=read-write
diff -rN -u old-smederee/modules/hub/src/main/scala/de/smederee/hub/VcsRepositoryRoutes.scala new-smederee/modules/hub/src/main/scala/de/smederee/hub/VcsRepositoryRoutes.scala
--- old-smederee/modules/hub/src/main/scala/de/smederee/hub/VcsRepositoryRoutes.scala	2025-02-02 09:48:36.768627283 +0000
+++ new-smederee/modules/hub/src/main/scala/de/smederee/hub/VcsRepositoryRoutes.scala	2025-02-02 09:48:36.772627289 +0000
@@ -532,6 +532,73 @@
       } yield resp
   }
 
+  private val forkRepository: AuthedRoutes[Account, F] = AuthedRoutes.of {
+    case ar @ POST -> Root / UsernamePathParameter(repositoryOwnerName) / VcsRepositoryNamePathParameter(
+          repositoryName
+        ) / "fork" as user =>
+      ar.req.decodeStrict[F, UrlForm] { urlForm =>
+        for {
+          csrf  <- Sync[F].delay(ar.req.getCsrfToken)
+          owner <- vcsMetadataRepo.findVcsRepositoryOwner(repositoryOwnerName)
+          loadedSourceRepo <- owner match {
+            case None        => Sync[F].pure(None)
+            case Some(owner) => vcsMetadataRepo.findVcsRepository(owner, repositoryName)
+          }
+          // TODO Replace with whatever we implement as proper permission model. ;-)
+          sourceRepository = loadedSourceRepo.filter(r => r.isPrivate === false)
+          // Check if a repository with that name already exists for the user.
+          loadedTargetRepo <- vcsMetadataRepo.findVcsRepository(user.toVcsRepositoryOwner, repositoryName)
+          targetRepository = loadedTargetRepo.fold(
+            sourceRepository.map(_.copy(owner = user.toVcsRepositoryOwner))
+          )(_ => None)
+          targetUri <- Sync[F].delay(
+            linkConfig.createFullUri(
+              Uri(path =
+                Uri.Path(
+                  Vector(
+                    Uri.Path.Segment(s"~${user.name.toString}"),
+                    Uri.Path.Segment(repositoryName.toString)
+                  )
+                )
+              )
+            )
+          )
+          sourceDirectory <- Sync[F].delay(
+            Paths.get(
+              darcsConfig.repositoriesDirectory.toString,
+              repositoryOwnerName.toString,
+              repositoryName.toString
+            )
+          )
+          targetDirectory <- Sync[F].delay(
+            Paths.get(
+              darcsConfig.repositoriesDirectory.toString,
+              user.name.toString,
+              repositoryName.toString
+            )
+          )
+          output <- targetRepository match {
+            case None => Sync[F].pure(0)
+            case Some(repoMetadata) =>
+              for {
+                _ <- Sync[F].delay(
+                  Files.createDirectories(
+                    Paths.get(darcsConfig.repositoriesDirectory.toString, repoMetadata.owner.name.toString)
+                  )
+                )
+                darcsClone <- darcs.clone(sourceDirectory, targetDirectory)(Chain("--complete"))
+                createRepo <-
+                  if (darcsClone.exitValue === 0)
+                    vcsMetadataRepo.createVcsRepository(repoMetadata)
+                  else
+                    Sync[F].pure(0) // Do not create DB entry if darcs init failed!
+              } yield createRepo
+          }
+          resp <- SeeOther(Location(targetUri))
+        } yield resp
+      }
+  }
+
   private val parseCreateRepositoryForm: AuthedRoutes[Account, F] = AuthedRoutes.of {
     case ar @ POST -> Root / "repo" / "create" as user =>
       ar.req.decodeStrict[F, UrlForm] { urlForm =>
@@ -725,7 +792,7 @@
   }
 
   val protectedRoutes =
-    showAllRepositories <+> showRepositories <+> parseCreateRepositoryForm <+> showCreateRepositoryForm <+> showRepositoryOverview <+> showRepositoryHistory <+> showRepositoryFiles
+    forkRepository <+> showAllRepositories <+> showRepositories <+> parseCreateRepositoryForm <+> showCreateRepositoryForm <+> showRepositoryOverview <+> showRepositoryHistory <+> showRepositoryFiles
 
   val routes =
     cloneRepository <+> showAllRepositoriesForGuests <+> showRepositoriesForGuests <+> showRepositoryOverviewForGuests <+> showRepositoryHistoryForGuests <+> showRepositoryFilesForGuests
diff -rN -u old-smederee/modules/hub/src/main/twirl/de/smederee/hub/views/showRepositoryOverview.scala.html new-smederee/modules/hub/src/main/twirl/de/smederee/hub/views/showRepositoryOverview.scala.html
--- old-smederee/modules/hub/src/main/twirl/de/smederee/hub/views/showRepositoryOverview.scala.html	2025-02-02 09:48:36.768627283 +0000
+++ new-smederee/modules/hub/src/main/twirl/de/smederee/hub/views/showRepositoryOverview.scala.html	2025-02-02 09:48:36.772627289 +0000
@@ -51,6 +51,23 @@
                 </fieldset>
               </form>
             </dd>
+            @for(account <- user) {
+              @if(vcsRepository.owner === account.toVcsRepositoryOwner) {
+              <!-- Cloning/Forking a repo to ourself is disabled. -->
+              } else {
+              <dt>@Messages("repository.overview.clone.fork")</dt>
+              <dd>
+                <form action="@actionBaseUri.addSegment("fork")" method="POST" accept-charset="UTF-8" class="pure-form">
+                  <fieldset>
+                    @csrfToken(csrf)
+                    <div class="pure-controls">
+                      <button type="submit" class="pure-button">@Messages("form.fork.button.submit")</button>
+                    </div>
+                  </fieldset>
+                </form>
+              </dd>
+              }
+            }
           </dl>
         </div>
       </div>