From Valve Developer Community
SteamPipe is Steam's new content distribution system. It changes the way games (including dedicated servers) are downloaded, updated and stored. More information can be found on the Steam Support page.
The benefits to players are:
- Faster and smoother downloads
- Faster game boot times and map load times
- Easier distribution, installation, and management of mods
- Smoother dedicated server distribution and update rollover
Instead of a proprietary delivery protocol, SteamPipe uses HTTP, which allows datacenters hosting multiple servers to set up a caching HTTP proxy, necessitating only a single download of an update from Valve's servers.
Game developers using SteamPipe can issue updates themselves; the previous system required manual intervention by Valve when an update was to be published.
The only real downside to the Steampipe update is that many Half-Life and Half-Life 2 mods that are now broken, and many that did not make the jump to the update.
Fortunately, there are known fixes for many Half-Life 2 mods. Those fixes can be found here.
The Source SDK Launcher no longer works. Tools must now be launched by going to " C:\Program Files (x86)\Steam\SteamApps\common\Half-Life 2\bin "
- Downloads are performed using HTTP instead of a proprietary protocol.
- Data files are no longer placed into GCFs but directly into the file system.
- Data generated before/during gameplay is no longer stored in user-specific subdirectories of SteamApps; instead, the common subfolder is used.
- Dedicated servers are no longer updated using HLDSUpdateTool (known as steam on Linux) but using SteamCMD (a stripped-down version of the full Steam client).