I’m giving Startools and ASTAP a plug
ASTAP is open source freeware and stacks OSC and Mono data sets on any system platform. It’s right up there with Pixinsight
https://www.hnsky.org/astap.htm
Startools is post processing software which uses a signal evolution tracking engine to process your data ( not traditional processing with levels , curves and a miriad of settings and assumptions)
One off low cost, intuitive and suitable for both beginners and advanced imagers
https://www.startools.org/
Cheers
Martin