Modifikace is a Czech news and review site for single player Half-Life 1.

PlanetPhillip.com contains the most comprehensive database of single player maps and mods for the Half-Life series of game on the Internet.

Podcast 17 is a weekly verbal tour of the Half-Life community. It covers everything related to the Half-Life universe and features lively, informative recordings.

SteamCard is a simple way to display your stats from the Steam Community, just like a Live! Gamercard. SteamCards are just PNG images, which means you can embed them into forums, signatures etc. Different styles of SteamCard are avaliable so you can stand out from the crowd.

The Half-Life Saga Story Guide was created in order to provide a concise, accurate, user-friendly overview of the events dealing directly with the events of the Half-Life Saga, and allowing users to easily get a better understanding of the story behind the games. It was written by Chan Karunamuni, with lots of help from contributions [...]

The Snarkpit has been online since 2001, making it one of the longest running websites that covers Valve’s games. It has had a number of redesigns over the years and always adds new features.

The Whole Half-Life AKA TWHL is first and foremost a community of mappers and modders. It has very active forums and plenty of tutorials.