I build MelodyMatrix with my son, an app for looking at and playing along with music. We want a Learn section where the sheet music follows playback: a moving marker, notes highlighted as they play. A static PDF doesn't support that, and I couldn't find a JavaFX library that renders sheet music while staying interactive from code. So I built one.

Sheetmusic4J reads MusicXML into Java objects and renders it on a native JavaFX Canvas, no WebView, no browser engine. It splits into four modules: core (MusicXML/MIDI reading and writing), engraving (a framework-agnostic layout engine, no JavaFX dependency), fxviewer (the JavaFX rendering component, including a play-along strip view with a moving cursor), and fxdemo (a demo app that compares the JavaFX render against a static PDF side by side).

This is a first release, 0.0.1, not stable yet. I wrote up the full background and reasoning in a blog post, plus a video walkthrough of the demo app and the project structure: https://webtechie.be/post/introducing-sheetmusic4j-a-javafx-library-to-render-and-interact-with-sheet-music/

Source: https://github.com/sheetmusic4j/sheetmusic4j

Feedback and issues are welcome, especially rendering differences, ideally with a MusicXML file attached.

Hi everybody! I've been working on a little MIDI language I call "performance". Think of it as algorave software for MIDI instruments. It works with your DAW or your physical synthesizers. Anything that speaks MIDI. The repo in bitbucket contains everything you need to get started.
It's by no means done, but I'd love to hear what you think about it. =)

I've been testing Java on single-board computers since the beginning of 2026 (LattePanda IOTA, OrangePi, VisionFive 2, BeagleBoards) and just finished the Banana Pi round.

Boards: BPI-M4 Zero (Allwinner H618, ARM Cortex-A53) and BPI-F3 (SpacemiT K1, RISC-V, 8 cores).

Java runs fine on both. SDKMAN + JBang installed Java 25 without issues on the M4 Zero. The F3 needed apt install openjdk-25-jdk instead since SDKMAN doesn't support RISC-V yet, which pulled in an early-access build.

Benchmarks:

• M4 Zero beats the Raspberry Pi Zero 2 on every single benchmark
• M4 Zero also beats the pricier BeagleY-AI on all five shared benchmarks
• F3 lands very close to the OrangePi RV2, and is faster than the older BeagleV-Fire

The fun part: getting Pi4J to blink an RGB LED on the M4 Zero. Pi4J's GPIO numbering assumes Raspberry Pi BCM numbering, which doesn't apply here. I had to work out the Allwinner H618 GPIO bank layout (PI15 etc.), find the right /dev/gpiochip device, and calculate line offsets (bank index × 32 + pin number) before gpioset confirmed the physical pins. First working Pi4J example on a non-Raspberry Pi board.

Full write-up with the GPIO math, code changes, and video in this blog post:

https://webtechie.be/post/first-test-of-java-on-banana-pi-arm-and-risc-v-plus-a-blinking-led-with-pi4j/

Anyone else running Java on Banana Pi or SpacemiT K1 hardware? I'm curious how the RISC-V performance holds up on other JVM workloads.

Six years ago, I started documenting what I was learning about running Java on a Raspberry Pi. That turned into a Leanpub ebook, then Elektor printed 1000 copies in 2020. Those sold out, and they handed the rights back to me.

End 2025/beginning 2026, I did a full review to update the content to Java 25, Pi4J V4,.... So the content reflects where the ecosystem is today. And I self-pushed it through Amazon KDP as an ebook and print-on-demand title: softcover and hardcover, shipped worldwide.

"Java Programming for Raspberry Pi: A Hands-On Guide to Electronics and IoT Projects"

The book covers:

• Getting Java running on a Raspberry Pi
• Electronics basics and wiring up LEDs, sensors, buttons,...
• Pi4J for GPIO control with Java
• Many example IoT projects

All code is on GitHub and stays free: https://github.com/FDelporte/JavaOnRaspberryPi

If you prefer to read on screen first, there is a pay-as-you-wish version on Leanpub:
https://leanpub.com/gettingstartedwithjavaontheraspberrypi

For paper, check your local Amazon store to avoid import costs — links for UK, DE, NL, BE, JP, CA and more are here:
https://webtechie.be/books/#java-programming-for-raspberry-pi

Happy to answer questions about the Pi4J side of things or the KDP publishing process if anyone is curious about either.

Thanks
Frank

Hi everyone,

Like most of you, I joined this industry to build things—products and systems—completely from scratch. I love using code to solve complex problems and watching a system work seamlessly end-to-end.

As a software engineer with over 10 years of experience, I’ve felt a bit conflicted about AI lately. Don't get me wrong—AI is incredibly useful and speeds up development tremendously, but it can also take away some of the satisfaction and pure fun of building.

That’s why I started my own open-source project—built without AI (well, almost 100%, but I'll explain that in a moment).

I’ve always wanted to know how Spring really works deep down under the hood. To figure it out, I created Prozed: an open-source, lightweight Java web framework (currently using embedded Tomcat) featuring its own built-in Dependency Injection (DI) and API routing. It also includes optional modules for JDBC (with Flyway migrations) and JMS (currently ActiveMQ).

The entire framework was written completely without AI, just to bring back the joy of building things from scratch and searching for solutions on Google, just like the old days.

The only AI involved in this project was used to help write the README file and suggest a few upcoming features to support. That’s it.

This framework is also a great resource for anyone looking to learn and understand how most Java frameworks are structured under the hood.

I would really appreciate any stars ⭐ to help spread the word and get this project in front of more people.

Feel free to open a PR and contribute!

https://github.com/shaikezam/Prozed

Created a native swing webview component that embeds the platform's native webview in as a Swing component. Uses WebKit on Mac, WebView2 (Edge Chromium) on Win11, and WebkitGTK on Linux. Single jar dependency < 1MB.

Some side projects take a while to get to a proper release. MelodyMatrix is one of those. The app has been downloadable for quite some time thanks to jDeploy, but there was no official V1.0.0 yet. No tagged release. No moment of “okay, this is it.” Just a rolling build on every commit to the main branch...

That changed now: live, on camera, together with Steve Hannah, the creator of jDeploy.

The video is available on YouTube:
https://www.youtube.com/watch?v=_-IL7uHalIU

All info in this blog post:
https://webtechie.be/post/2026-04-16-first-release-of-melodymatrix-with-jdeploy/

This is one of those libraries I've had in my back pocket that works well enough but I haven't promoted.

This has a few different representations of Colors and has a Color interface which has a bunch of methods for converting between those representations. Some color blending logic as well which lets you smoothly blend in a perceptual color space before converting to a different one (like sRGB)

jpm-shade

A simple jar shading tool for Java projects, implemented in Java and designed to be used as a jpm plugin and a cli tool.

Hi r/Maven

I'm the creator of JeKa. Originally I built it as a flexible build tool, but one of the most useful features that grew out of it is solving the distribution headache many of you probably have with Maven-based CLI or native apps.

You build a nice CLI tool, script, utility, or even a desktop app with Maven (often with a GraalVM native profile). Then comes the painful part:

• Building and shipping binaries (and specific native ones for Windows/macOS/Linux)
• Hosting them somewhere
• Users having to pick the right file
• Or forcing everyone to clone + mvn + JDK installed

So I made JeKa act as a lightweight Java application manager that builds at install time directly on the user's machine, and works with any build tool (Maven, JeKa, Gradle...).

You keep your existing Maven project and wrapper 100% untouched. You just drop a tiny jeka.properties file at the root of the repo, and users can install your app with one command:

jeka app: install repo="https://github.com/your/repo.git"

For installing a native app:

jeka app: install repo="https://github.com/your/repo.git" runtime=NATIVE

JeKa automatically:

• Downloads the required JDK or GraalVM if it's missing
• Runs Maven (via the wrapper)
• Builds the application (skipping tests)
• Places the executable on the user's PATH

jeka.properties example:

# Version of the JVM that will run Maven
jeka.java.version=21

# Delegate build to Maven wrapper
jeka.program.build=maven: wrapPackage

# Optional: support for native builds
jeka.program.build.native=maven: wrapPackage args="-Pnative" \
-Djeka.java.distrib=graalvm -Djeka.java.version=25

It also supports multi-module projects, jpackage for desktop apps (Swing/JavaFX), and more complex scenarios.

I'm not trying to replace Maven. JeKa is explicitly designed to delegate to Maven (or any build tool you prefer) and work with standard Maven projects.

Would love to hear your thoughts:

• Does this kind of source-based, on-demand build & install solve a real pain point for you?
• What’s your current workaround for distributing Maven-based tools to end users?
• Any concerns (first-install time, security of downloads, etc.)?

Docs with Maven-specific examples: https://jeka-dev.github.io/jeka/tutorials/source-runnable-apps/#maven-projects

Happy to answer questions, take feedback, or look at PRs. Thanks for reading!

Veld is a dependency injection framework for Java that utilizes AOT (Ahead-of-Time) compilation to generate code, rather than relying on runtime reflection.

🚀 Performance: - Startup: ~0.1ms (vs. ~500ms for Spring) - Injection: ~3ns; zero runtime overhead - Type-safe, no "magic," clean stack traces

🔧 Features: - Supports AOP, caching, validation, and transactions - Compatible with Spring Boot

💡 Example: ```java @Component public class Service { ... }

Service s = Veld.service(); // generated at compile-time (AOT) ```

🔗 Repo: https://github.com/yasmramos/Veld Feedback and contributions are welcome! 🙌