Skyrim Skse 1.6.640 [extra Quality] Site

Developers targeting SKSE 1.6.640 use:

If all of these are true, you now have one of the most stable, powerful, and well-supported versions of modded Skyrim in existence. Version 1.6.640 might be a middle child in Bethesda’s update timeline, but for the savvy modder, it is the Gold Standard. skyrim skse 1.6.640

If you see a mod that says "Requires 1.5.97," do not use it on 1.6.640. You will CTD. Developers targeting SKSE 1