Adding to the companies mentioned un other comments, there's also some interesting work going on developing open hardware and open software for #bitcoinmining .
You can follow the progress on some projects: #bitaxe (by nostr:npub1ql2zzp3g6yndgz05js7wdc4qkr88wkyne5nw2cc7csrtzqs0yeesgwrxya ) or #nerdminer (by bitmaker@nostrplebs.com, still not using ASIC though)