Everything on Steam, newest first: games, DLC, demos, playtests, software, tools, soundtracks and videos. New ones appear within seconds of Steam adding them.
On Steam, an app is one product: a game, a DLC, a demo, a soundtrack, a piece of software. Each has its own number (the App ID, the number in its store link), usually its own store page and community hub, and it is what shows up in your library.
You don't buy apps directly: you buy or activate a package, which unlocks one or more apps.
| App | Type | Released | Playing now | Owners (est.) |
|---|---|---|---|---|
 Portal 2 Publishing ToolApp 644 | Tool | — | 3 | — |
 Alien Swarm - SDKApp 640 | Tool | — | 0 | — |
 Alien Swarm Dedicated ServerApp 635 | Tool | — | 3,662 | — |
 Portal 2 Authoring ToolsApp 629 | Tool | — | 23 | — |
 Left 4 Dead 2 Authoring ToolsApp 563 | Tool | — | 38 | — |
 Left 4 Dead Demo Dedicated Server |
We read every app on Steam continuously, so this list fills in and stays current on its own. Owners are SteamSpy's estimate for games and software; † marks an estimate from the app's Steam review count (about 20 to 60 owners per review), used for DLC, soundtracks and the rest.
| Tool |
| — |
| 0 |
| — |
 Left 4 Dead Authoring ToolsApp 513 | Tool | — | 3 | — |
 Left 4 Dead Dedicated ServerApp 510 | Tool | — | 0 | — |
 Source 2007 Dedicated ServerApp 310 | Tool | — | 0 | — |
 Source SDK Base 2007App 218 | Tool | — | 9,644 | — |
 Source SDK Base 2006App 215 | Tool | — | 0 | — |
 Source SDKApp 211 | Tool | — | 72 | — |
 Source Dedicated ServerApp 205 | Tool | — | 0 | — |
 Half-Life Dedicated ServerApp 90 | Tool | — | 1 | — |
