What is “Scala Presentation Compiler”?

Question

What is the \"Scala Presentation Compiler\"?

Answer 1

It's a compiler that provides the hooks necessary to work well to support the interactive features of an IDE, like color-coding, autocompletion, etc. One of the technical challenges is efficiently staying in sync with what's been edited. See this talk.

Answer 2

The Scala Presentation Compiler is provided as part of Scala so that IDEs can have access to the intermediate information that doesn't make it into the final compiled output.

A quick googling gives this. Odersky also discussed it in this (very interesting) talk about what's coming in Scala 2.10 (at about 22 minutes in).