Beyond All Reason – open-source RTS game built on top of the Recoil RTS Engine
github.comZero-K is a similar game (also opensource, built on same engine, slightly different design goals): https://zero-k.info/ https://store.steampowered.com/app/334920/ZeroK/
Zero-K simplified the economy (metal cost = energy cost) but added a whole lot of mechanics like overdrive grids and made every unit unique. There is a lot more unit variety with mind-control, jumpjets, shields, unit-throwers, self-replicators, teleports, terraforming, etc.
Their design blog is also very interesting: https://zero-k.info/mediawiki/Cold_Takes
An ongoing discussion about OpenRA may interest this audience: https://news.ycombinator.com/item?id=42823667
Very closely follows the style of Total Annihilation, a 4X game I spent a fantastic amount of time in.
Perhaps still the only game whose loading screen dedicates time to loading explosions!
I was surprised there weren't more prior submissions, but one for their website did have some commentary back in 2021 https://news.ycombinator.com/item?id=28201265