# \#opensource
**URL:** https://forum.babylonjs.com/tag/opensource/381.md
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## [\[OPEN SOURCE\] Multiplayer 3D RPG Using Colyseus](https://forum.babylonjs.com/t/open-source-multiplayer-3d-rpg-using-colyseus/35733)
**Author:** [@oriongu](https://forum.babylonjs.com/u/oriongu)\
**Replies:** 372\
**Last updated:** [May 25, 2026, 11:03am UTC](https://forum.babylonjs.com/t/open-source-multiplayer-3d-rpg-using-colyseus/35733 "2026-05-25T11:03:42Z")
Hi there, First of all, great job to all those who made babylon.js, it’s feels great to use, has a great commmunity, it’s constantly evolving and got many tools to achieve your outcome. After scouring the forum for a w…
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## [\[Open Source MMORPG\] MU Online Client](https://forum.babylonjs.com/t/open-source-mmorpg-mu-online-client/52548)
**Author:** [@Alexander\_Sosnovskiy](https://forum.babylonjs.com/u/Alexander_Sosnovskiy)\
**Replies:** 10\
**Last updated:** [July 10, 2025, 4:32am UTC](https://forum.babylonjs.com/t/open-source-mmorpg-mu-online-client/52548 "2025-07-10T04:32:30Z")
Hello guys! I used to play a lot in MU in my childhood. And it was a dream to have mobile or web version to play not only on PC. And after 15 years I have enough experience to implement some of the features using Babylo…
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## [\[OPEN SOURCE\] ECS for Babylon](https://forum.babylonjs.com/t/open-source-ecs-for-babylon/49569)
**Author:** [@pjoe](https://forum.babylonjs.com/u/pjoe)\
**Replies:** 9\
**Last updated:** [April 18, 2024, 12:27pm UTC](https://forum.babylonjs.com/t/open-source-ecs-for-babylon/49569 "2024-04-18T12:27:16Z")
We have been testing out existing ECS libraries, but found we wanted something more Babylon “native” and ended up creating bjs-ecs (published on npm) Source is on GitHub. Feel free to reach out if interested in collabo…