Language-agnostic pretty-printing through machine learning (uh, like, is this possible? YES, apparently).
Grammars written for ANTLR v4; expectation that the grammars are free of actions.
ANTLR (ANother Tool for Language Recognition) is a powerful parser generator for reading, processing, executing, or translating structured text or binary files.
antlr v3 repository (pulled from p4 with history from //depot/code/antlr/antlr3-main
A sample plugin for jetbrains IDEs that uses an ANTLR grammar for a nontrivial custom language.
A library to support the use of ANTLR grammars in jetbrains IDE plugins for building custom languages.
Grammars written for ANTLR v3; expectation that the grammars are free of actions but it's not a hard and fast rule. there is no common license!