Some things claim to be, but not really.
You can write down the list of sharepoint features you need, and then find individual OSS projects that fill the gap. It's not a one-stop thing, but it doesn't have to be a deal breaker either.
You can write down the list of sharepoint features you need, and then find individual OSS projects that fill the gap. It's not a one-stop thing, but it doesn't have to be a deal breaker either.