OStatus is a suite of protocols for distributed social networking: Atom ActivityStreams, PubSubHubbub, Salmon, WebFinger per https://twitter.com/kevinmarks/status/365560040326840320 / Evan Prodromou, who later went on to develop pump.io, which itself is being superseded by ActivityPub.
Here's a table of OStatus technologies and current IndieWeb equivalents that are being adopted:
|syndication format||Atom ActivityStreams||h-feed and h-entry|
|publishing notifications||PubSubHubbub||PubSubHubbub (0.4 arbitrary content)|
|discovery / identity||WebFinger||rel-me|
Related (semi-generationally) but not officially part of OStatus:
The indieweb equivalents are typically a subset and do not achieve the same levels of functionality as the OStatus technologies, however the indieweb equivalents are what's been developed so far to meet current use-cases.