Does anyone know how I can cross-compile software for a 1999 iMac G3 with a PowerPC processor? Are there resources on how to develop for this CPU and is there any community around it?
Take a look at https://recapamac.com.au/ . The chap is no longer in the recapping business, but offers some helpful resources. Also consider replacing the PRAM battery -- I'm not a vintage iMac expert but know that this has been an issue with other older Macs.