diff --git a/README.md b/README.md
index 6b802ac..968e275 100644
--- a/README.md
+++ b/README.md
@@ -3,6 +3,8 @@ CI worker for processing RiverBench datasets and other repositories.
 
 Please file issues, bugs, and other requests in the **[main issue tracker](https://github.com/RiverBench/RiverBench/issues)**.
 
+This project uses Scala Next (3.8.4) and JDK 25.
+
 ## Usage
 In the container, use `ci-worker <args>` to run the worker.
 
diff --git a/src/main/scala/commands/DatasetDocGenCommand.scala b/src/main/scala/commands/DatasetDocGenCommand.scala
index 70ed1df..805be8c 100644
--- a/src/main/scala/commands/DatasetDocGenCommand.scala
+++ b/src/main/scala/commands/DatasetDocGenCommand.scala
@@ -170,7 +170,8 @@ object DatasetDocGenCommand extends Command:
         |### Download links
         |
         |The dataset is published in a few size variants, each containing a specific number of stream elements.
-        |For each size, there are three distribution types available: flat (just an N-Triples/N-Quads file),
+        |For each size, there are three distribution types available: flat
+        |(an N-Triples/N-Quads file in the [RDF Message Log format](https://w3c-cg.github.io/rsp/spec/messages)),
         |streaming (a .tar.gz archive with Turtle/TriG files, one file per stream element),
         |and [Jelly](https://w3id.org/jelly) (a native binary format for streaming RDF).
         |See the [documentation](../../documentation/dataset-release-format.md) for more details.
diff --git a/src/main/scala/commands/PackageCommand.scala b/src/main/scala/commands/PackageCommand.scala
index fcb1251..0c46253 100644
--- a/src/main/scala/commands/PackageCommand.scala
+++ b/src/main/scala/commands/PackageCommand.scala
@@ -328,6 +328,12 @@ object PackageCommand extends Command:
     }
     StreamUtil.broadcastSink(sinks)
 
+  /**
+   * RDF Messages delimiter.
+   * https://w3c-cg.github.io/rsp/spec/messages#message-delimiter
+   */
+  private val messageDelimiter = "MESSAGE\n".getBytes
+
   private def packageFlatSerializeFlow(metadata: MetadataInfo): Flow[(DatasetGraph, Long), ByteString, NotUsed] =
     Flow[(DatasetGraph, Long)]
       .map((ds, _) => ds.find().asScala.toSeq.sorted)
@@ -341,9 +347,13 @@ object PackageCommand extends Command:
           val writer = StreamRDFWriter.getWriterStream(os, Lang.NQUADS)
           quads.foreach(q => writer.quad(q))
           writer.finish()
+        os.write(messageDelimiter)
         os.toByteArray
       })
       .map(ByteString.fromArrayUnsafe)
+      // RDF Messages version announcement
+      // https://w3c-cg.github.io/rsp/spec/messages#version-announcement
+      .prepend(Source.single(ByteString("VERSION \"1.1-messages\"\n")))
 
   /**
    * Creates a sink that writes the data to flat files
diff --git a/src/main/scala/util/io/SaveResult.scala b/src/main/scala/util/io/SaveResult.scala
index 769e4b7..601509d 100644
--- a/src/main/scala/util/io/SaveResult.scala
+++ b/src/main/scala/util/io/SaveResult.scala
@@ -19,6 +19,8 @@ case class SaveResult(io: IOResult, name: String, size: Long, md5: String, sha1:
 
     dType match
       case DistType.Flat =>
+        // Flat files using the RDF Message Log format:
+        // https://w3c-cg.github.io/rsp/spec/messages#turtle
         if mi.streamTypes.exists(_.elementType == ElementType.Triple) then
           distRes.addProperty(RdfUtil.dcatMediaType, "application/n-triples")
         else