Okay - so, Wrath of the Vohven. I would've written this up sooner, but I've been reading through the awesome thread on Tomb of Horrors. Side bar - as a player who is relatively new to the genre (been slinging dice since 98), I missed out on allllllll the good, old modules. For whatever it's worth, though, I get the feeling that HackMaster very strongly emulates the feel of Gary's old work.
The basic premise behind Wrath of the Vohven is "Heart of Darkness" in HackMaster. A very powerful mage goes rogue, enters the jungle, and eventually finds himself controlling a large stake in items traded to the Jade Lion Trading Company, not to mention a tribe of Lizard Men who view him in awe.
The module does an excellent job of explaining what Svimohzia is - not to mention it provides a pronunciation guide. There's general information about the major cities, a two-page map of the jungle area in which the adventure is situated, as well as new proficiencies for the game (skinning/tanning, taxidermy).
The actual meat of the adventure begins with the PCs being recruited and going into the jungle. (There are some great random encounters which might occur, including with some new HM monsters.) The PCs have a lot of options here, primarily focusing on a variety of short-adventure jobs that their recruiter asks them to perform.
Probably the single most interesting looking (to me) scenario is the copper mine, although, for those crazy gamers out there who dislike dungeon crawls there is plenty else to do besides kill monsters in narrow corridors. Each section of the mine is mapped, and each room number is clickable. In other words, the GM can click "A2" and be immediately directed to the proper page to read the necessary flavor to his players. The mines are massive and, for obvious reasons, are brimming with cool things to find and kill.
(I should also note that there are many, many inner-document links that take you to the right area.)
At the end of the book are sizable appendices - these provide details on making PCs that are Svimohzish in heritage, among others. Also included are several complete HoB entries, for Apes (gorilla and killer), the Rhesus Monkey, crocodiles, haunts, hippos and flesh eating slimes.
Further included is a KODT article by Jolly that describes how to make a Hack Track (posted below is a picture of mine), and then
43 pages of monster cards. (It should be noted that these are exclusive to the pdf and will not be included in the dead tree edition... which is why buying the pdf plus dead tree copy for only an extra $5 is a steal).
Anyway - this adventure is definitely worth it, and similar to Frandor's Keep in how there are several sub-adventures which are connected to the all-encompassing overall theme of finding the mage who disappeared in the jungle. Should you buy it? Actually, my question is why haven't you bought it already? If you never play HackMaster, you'll still have tons of new ideas that you can mine for your own games - not to mention how easy it is to browse the pdf (and this is really something that every gaming company needs to do - it's an incredibly innovative idea). And the monster cards are really exciting - I love mine, anyway.