diff --git a/.forgejo/workflows/release.yaml b/.forgejo/workflows/release.yaml
index 71078ca..d921da5 100644
--- a/.forgejo/workflows/release.yaml
+++ b/.forgejo/workflows/release.yaml
@@ -32,18 +32,42 @@ jobs:
           username: ${{ secrets.FORGEJO_USER }}
           password: ${{ secrets.FORGEJO_TOKEN }}
 
-      - name: Build docker image - base
+      - name: Build - executor-ubuntu
         uses: docker/build-push-action@v4
         with:
-          file: Dockerfile
+          file: Dockerfile-ubuntu
           push: true
           tags: |
-            git.myservermanager.com/msm/forgejo-base-executor-image:latest
+            git.myservermanager.com/msm/executor-ubuntu:latest
 
-      - name: Build docker image - make cgo
+      - name: Build - executor-ubuntu-build-essential
         uses: docker/build-push-action@v4
         with:
-          file: Dockerfile-make-cgo
+          file: Dockerfile-ubuntu-build-essential
           push: true
           tags: |
-            git.myservermanager.com/msm/forgejo-base-executor-image-make-cgo:latest
+            git.myservermanager.com/msm/executor-ubuntu-build-essential:latest
+
+      - name: Build - executor-ubuntu-ruby
+        uses: docker/build-push-action@v4
+        with:
+          file: Dockerfile-ubuntu-ruby
+          push: true
+          tags: |
+            git.myservermanager.com/msm/executor-ubuntu-ruby:latest
+
+      - name: Build - executor-alpine
+        uses: docker/build-push-action@v4
+        with:
+          file: Dockerfile-alpine
+          push: true
+          tags: |
+            git.myservermanager.com/msm/executor-alpine:latest
+
+      - name: Build - executor-alpine-java21
+        uses: docker/build-push-action@v4
+        with:
+          file: Dockerfile-alpine-java21
+          push: true
+          tags: |
+            git.myservermanager.com/msm/executor-alpine-java21:latest
diff --git a/.forgejo/workflows/release_rebuild.yaml b/.forgejo/workflows/release_rebuild.yaml
index b457e2b..fd3785f 100644
--- a/.forgejo/workflows/release_rebuild.yaml
+++ b/.forgejo/workflows/release_rebuild.yaml
@@ -31,18 +31,42 @@ jobs:
           username: ${{ secrets.FORGEJO_USER }}
           password: ${{ secrets.FORGEJO_TOKEN }}
 
-      - name: Build docker image - base
+      - name: Build - executor-ubuntu
         uses: docker/build-push-action@v4
         with:
-          file: Dockerfile
+          file: Dockerfile-ubuntu
           push: true
           tags: |
-            git.myservermanager.com/msm/forgejo-base-executor-image:latest
+            git.myservermanager.com/msm/executor-ubuntu:latest
 
-      - name: Build docker image - make cgo
+      - name: Build - executor-ubuntu-build-essential
         uses: docker/build-push-action@v4
         with:
-          file: Dockerfile-make-cgo
+          file: Dockerfile-ubuntu-build-essential
           push: true
           tags: |
-            git.myservermanager.com/msm/forgejo-base-executor-image-make-cgo:latest
+            git.myservermanager.com/msm/executor-ubuntu-build-essential:latest
+
+      - name: Build - executor-ubuntu-ruby
+        uses: docker/build-push-action@v4
+        with:
+          file: Dockerfile-ubuntu-ruby
+          push: true
+          tags: |
+            git.myservermanager.com/msm/executor-ubuntu-ruby:latest
+
+      - name: Build - executor-alpine
+        uses: docker/build-push-action@v4
+        with:
+          file: Dockerfile-alpine
+          push: true
+          tags: |
+            git.myservermanager.com/msm/executor-alpine:latest
+
+      - name: Build - executor-alpine-java21
+        uses: docker/build-push-action@v4
+        with:
+          file: Dockerfile-alpine-java21
+          push: true
+          tags: |
+            git.myservermanager.com/msm/executor-alpine-java21:latest
diff --git a/Dockerfile-alpine b/Dockerfile-alpine
new file mode 100644
index 0000000..2b42d1f
--- /dev/null
+++ b/Dockerfile-alpine
@@ -0,0 +1,6 @@
+FROM alpine:3.20
+LABEL maintainer="msm <hostmaster@myservermanager.com>"
+
+RUN <<EOF
+apk add nodejs npm git docker docker-cli-buildx
+EOF
diff --git a/Dockerfile-alpine-java21 b/Dockerfile-alpine-java21
new file mode 100644
index 0000000..9513bb5
--- /dev/null
+++ b/Dockerfile-alpine-java21
@@ -0,0 +1,6 @@
+FROM git.myservermanager.com/msm/executor-alpine
+LABEL maintainer="msm <hostmaster@myservermanager.com>"
+
+RUN <<EOF
+apk add openjdk21 unzip
+EOF
diff --git a/Dockerfile b/Dockerfile-ubuntu
similarity index 89%
rename from Dockerfile
rename to Dockerfile-ubuntu
index 814c9d6..bffc241 100644
--- a/Dockerfile
+++ b/Dockerfile-ubuntu
@@ -1,8 +1,6 @@
 FROM ubuntu:24.04
 LABEL maintainer="msm <hostmaster@myservermanager.com>"
 
-# base line required by Forgejo Runner: nodejs, npm, git
-# added: docker and buildx
 RUN <<EOF
 apt-get update
 apt-get install -y --no-install-recommends curl wget bash apt-transport-https ca-certificates gnupg nodejs npm git zstd
diff --git a/Dockerfile-make-cgo b/Dockerfile-ubuntu-build-essential
similarity index 59%
rename from Dockerfile-make-cgo
rename to Dockerfile-ubuntu-build-essential
index 0edc74f..4376f43 100644
--- a/Dockerfile-make-cgo
+++ b/Dockerfile-ubuntu-build-essential
@@ -1,6 +1,5 @@
-FROM git.myservermanager.com/msm/forgejo-base-executor-image
+FROM git.myservermanager.com/msm/executor-ubuntu
 
-# added: make and clang for CGO compile
 RUN <<EOF
 apt-get update
 apt-get install -y --no-install-recommends build-essential make clang
diff --git a/Dockerfile-ubuntu-ruby b/Dockerfile-ubuntu-ruby
new file mode 100644
index 0000000..b6860ab
--- /dev/null
+++ b/Dockerfile-ubuntu-ruby
@@ -0,0 +1,7 @@
+FROM git.myservermanager.com/msm/executor-ubuntu
+
+RUN <<EOF
+apt-get update
+apt-get install -y --no-install-recommends ruby ruby-dev rsync openssh-client
+rm -rf /var/lib/apt/lists/\* /tmp/\* /var/tmp/*
+EOF
diff --git a/README.md b/README.md
index 14f14a1..db44078 100644
--- a/README.md
+++ b/README.md
@@ -6,15 +6,17 @@ This git repository provides docker base images which can be used inside Forgejo
 
 All published images
 
-* are based on Ubuntu 24 LTS
 * inherit from the main base image, so they also include its packages
 * are re-published monthly
 * are published under the `git.myservermanager.com/msm/` space and _not_ in Docker Hub
 
-| Image name                             |                                Packages |
-| :------------------------------------- | --------------------------------------: |
-| `forgejo-base-executor-image`          | `nodejs` `npm` `docker` `docker-buildx` |
-| `forgejo-base-executor-image-make-cgo` |        `build-essential` `make` `clang` |
+| Base         | Image name                        |                                   Packages |
+| :----------- | :-------------------------------- | -----------------------------------------: |
+| Ubuntu 24.04 | `executor-ubuntu`                 |    `nodejs` `npm` `docker` `docker-buildx` |
+| Ubuntu 24.04 | `executor-ubuntu-build-essential` |           `build-essential` `make` `clang` |
+| Ubuntu 24.04 | `executor-ubuntu-ruby`            | `ruby` `ruby-dev` `rsync` `openssh-client` |
+| Alpine 3.20  | `executor-alpine`                 |    `nodejs` `npm` `docker` `docker-buildx` |
+| Alpine 3.20  | `executor-alpine-java21`          |                        `openjdk21` `unzip` |
 
 ### Usage
 
@@ -23,7 +25,7 @@ jobs:
   build:
     runs-on: docker
     container:
-      image: git.myservermanager.com/msm/forgejo-base-executor-image-make-cgo
+      image: git.myservermanager.com/msm/executor-ubuntu-build-essential
     steps:
       - name: Test
         run: |