- the longtime Curse Client, effectively an addon manager that started for World of Warcraft but now supports games like Rift, Skyrim, Minecraft, Kerbal Space Program
- CurseForge, the community site behind addon hosting and development
- the recent "Curse Voice" VOIP and chat client that is a direct competitor to Discord, and which got subsumed with the mod manager into the "Curse App"
- Gamepedia, a wiki host for video game wikis
Together with built-in streaming and just enough social networking, Twitch Desktop combines the best of Curse and Twitch to create a gamer hub that has more value-add than Steam -- largely a storefront -- and is similar to the new Blizzard App (previously known as the Blizzard Launcher or the Battle.net Launcher).
Blizzard's offering streams to Facebook Live, integrates with Facebook login, has a barebones but recently enhanced VOIP chat, and is the competitor with the most direct feature parity -- but captive to a publisher, and outsources all streaming to a third party.
7 months ago when Facebook announced that they're building a gaming hub, I wrote [1] that I'm not opposed to some social-ness in gaming, but real-name-based Facebook isn't the network most people want to conduct their gaming on.
Twitch is a gaming-focused YouTube and pseudonymous social network that can now offer a featureful, streaming, social, and chat application for download, and they're backed by a corporate parent that likes to sell you stuff. This is a pretty good match.