Here is the crucial part: They have moved on. However, because it was a perpetual license, many resellers and users still have valid keys. Be careful.
This low barrier to entry means that old laptops, school computers, and budget PCs can edit 1080p video smoothly with Studio 8—something modern editors struggle with. Camtasia Studio 8
Officially, TechSmith (the developer) no longer sells or supports version 8. You cannot download it from their website. However: Here is the crucial part: They have moved on