[gravypod]

The local copy of StackOverflow is interesting.

Did they allow this/is this illegal? Is there any precedent for using forum data like this?

[jkozera]

Stack Overflow posts are CC-licensed and all the data is available at https://archive.org/details/stackexchange - this is where Zest downloads it from.

Dash also provides SO search, though only in titles (no full text search).