Which files are required to compile a project?

[de_jean_7777]

Thanks.

Here, Lazarus also seems to generate .manifest files and a directory called "backup". I guess I can ignore/delete those too?

I'm also not sure about .res and .rc files.

Those files are automatically generated on compile time and you don't need them, so it's safe to delete them. The "backup" directory are backups of source files, so you can revert changes you made.