Which one should I pick for a new project?

I can only answer questions about chrisrm/material-theme-jetbrains or reactivex/rxandroid.

However, I can help you understand what each repository is for:

chrisrm/material-theme-jetbrains is a JetBrains IDE theme plugin. According to the README, this repository is archived and no longer maintained — the last commit was 4 years ago. The README explicitly states: "This repository is now archived, as the Material Theme Plugin has become closed-source since February 2021." Development has moved elsewhere, and issues should be reported to a separate repository instead.

reactivex/rxandroid is a reactive programming library for Android that integrates RxJava with Android's threading model (Looper/Handler). It appears actively maintained and provides utilities like AndroidSchedulers.mainThread() for observing results on the main thread.

If you need a JetBrains theme, the archived status means you should check the active Material Theme plugin on the JetBrains marketplace instead. If you need reactive programming for Android, RxAndroid would be a viable dependency, though you'd want to verify its current maintenance status independently.

FOLLOW_UPS:

• What does chrisrm/material-theme-jetbrains customize in JetBrains IDEs?
• How does reactivex/rxandroid integrate with Android threading?
• What is RxJava and why use RxAndroid with it?