Steamworks' new Custom Executable Generation (CEG) will supplement existing Steamworks' anti-piracy technology.
"CEG makes unique copies of games for each user, allowing them to access the application on multiple machines without install limits and without having to install root kits on their PC," Valve said in a statement.
CEG also supports in-game downloadable content and matchmaking. Developers have the ability to deliver new content to users, paid or free, within gaming sessions.
Steamworks' matchmaking now includes the lobby system used for the zombie shooter Left 4 Dead.
The additions marks Steamworks' first anniversary.
Today, Microsoft also announced improved anti-piracy measures and the ability for developers to create in-game storefronts within its own online PC gaming service, Games for Windows - Live.