J.A.C.K., VHLT v34 (Vluzacn's Half-Life Tools), and HL Texture Tools.
J.A.C.K. provides a nice set of features: Direction arrows for light_spot, light_environment and other entities that need such a thing, faithful model rendering, long file path support (Hammer never liked paths with spaces or ones that were too long, no more need to store stuff in C:/Hammer
), a much more comfortable-to-use Vertex Manipulation tool that now finally selects all parallel vertices when you try to select multiple ones with a single click, still runs on my 2005 HP Compaq yadda yadda yadda.
It's free, the paid version on Steam is... not something you'd wanna invest into right now. It's on hlfx.ru somewhere. Here, to be exact.
Either way, it has less quirks than Hammer. One of the quirks is to install J.A.C.K. somewhere NOT in Program Files or Program Files (x86) because it then wouldn't be able to write to its config files. Otherwise, should work just fine and peachy. Vluzacn's fork of ZHLT
, called VHLT, latest version being v34, is the state-of-the-art set of compilers for GoldSrc mapping. Basically, CSG, BSP and VIS are much faster, RAD takes a bit longer but delivers more beautiful lighting. It has func_detail, which is often useful if you've used func_wall a lot for small props and whatnot, though this feature has been available for a while, I believe. Same thing goes for ZHLT 2.x era light flags, where "blue" masked textures can cast shadows.HL Texture Tools
is pretty straightforward for WAD and sprite creation. WADs are standard, you just gotta have 8-bit BMPs, and in the case of masked textures, appropriate colour palettes. HL Texture Tools with sprites also allows you to easily change their orientation settings, something that can be pretty useful if you want 'fixed' sprites that don't face the player, but rather only a specific direction: Welcome back to the glorious mapping land. ^^