There is a site called altenativeto(dot)net that usually shows the more common alternatives.
It has filters for opensource/free software and there are comments on whether they are discontinued or not
Encrypt your drive/files.
I find Veracrypt useful for when you did not encrypt your drive don't/can't reformat your drive.
For drive, the os usually has a tool for encrypting entire drives (though iirc windows needs at least a pro version for that)