Support the Software Freedom Conservancy

The Software Freedom Conservancy helps Free/Open Source software projects by providing infrastructure, financial structures, and legal help. It is a not-for-profit organisation that is dedicated to software freedom, something that I think is an important prerequisite for a decent world in the future.

Conservancy looks after lots of projects, including these ones that I personally use: Boost, BusyBox, Etherpad, Git, Godot Engine, Inkscape, phpMyAdmin, QEMU, Racket, Samba, Selenium, Squeak and Wine.

It provides an easy way for projects to accept donations, hold assets and negotiate contracts, as well as mentoring and legal advice. It also leads the difficult and thankless work to persuade (and force) companies to comply with the GPL (a Free Software license). Without this work a great deal more Free Software would be distributed without the required access to source code, meaning it is not free at all.

Further, it is a key supporter of Outreachy, which does important work to address the under-representation, systemic bias, and discrimination in the technology industry.

I encourage you to join me and support the Software Freedom Conservancy.

You might also like to listen to the Free As In Freedom podcast.

Coding workshop example worksheets

This week we did a coding workshop exercise: 2 teams implemented the different sides of the SMPP protocol (without speaking to each other) and this morning we tried out connecting them together.

We successfully sent a message and received an acknowledgement!

It was a lot of fun and I we learned a surprising amount about SMPP (and quite how … interesting … the standard is).

In case they’re useful to anyone, here are the worksheets I made up: Team 1 ODT, Team 1 PDF, Team 2 ODT, Team 2 PDF.

Idea for a team who are less interested in SMPP (!) – try a similar exercise implementing FTP, which is a nice simple text-based protocol. I did this once and found it extremely rewarding.

Building an all-in-one Jar in Gradle with the Kotlin DSL

To build a “fat” Jar of your Java or Kotlin project that contains all the dependencies within a single file, you can use the shadow Gradle plugin.

I found it hard to find clear documentation on how it works using the Gradle Kotlin DSL (with a build.gradle.kts instead of build.gradle) so here is how I did it:

$ cat build.gradle.kts 
import com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar

plugins {
    kotlin("jvm") version "1.3.41"
    id("com.github.johnrengelman.shadow") version "5.1.0"

repositories {

dependencies {

tasks.withType<ShadowJar>() {
    manifest {
        attributes["Main-Class"] = "HelloKt"

$ cat src/main/kotlin/Hello.kt 
fun main() {

$ gradle wrapper --gradle-version 5.5
1 actionable task: 1 executed

$ ./gradlew shadowJar
2 actionable tasks: 2 executed

$ java -jar build/libs/hello-all.jar