J.A.C.K. Hammer Editor
ℹ️ This topic was not started by the developer of the software.
Brand new level editor for games with a Quake-style BSP architecture; a convenient cross-platform tool capable of incorporating the best features of existing editors, such as Valve Hammer Editor, Q3Radiant, and others. J.A.C.K. does aspire to be the universal level design tool for classic games.
Free Version: There is no usage limit. There is no usage limit. But it no longer receives updates.
Or download from Official website: https://jack.hlfx.ru/en/download.html
Paid Version: Purchase to support the developer. The best updates are coming to the Steam version.