There is OpenLieroX (https://www.openlierox.net/) (disclaimer: I'm one of the main developers) and then there is also a almost exact reimplementation of the original one (https://www.liero.be/).

Also see Webliero: https://news.ycombinator.com/item?id=22980676

And there have been many other clones in the past like Gusanos.

Soldat is also similar, and has recently become open sourced. https://news.ycombinator.com/item?id=26058312

And Teeworlds (always been open source) as well.

I did look at all the clones (there are many!) But I felt like none matched the dynamics and mechanics of the original -- hence my excitement when someone ported OpenLieroX and made the almost exact reimplementation!

Hah, I didnt know that about Liero, that's a great story.

I remember having many good days with classmates in our computer high school class "studying" thanks to LieroX