Esprima offers two very simple API function with the same input, i.e. a string that represents an ECMAScript code. The first function is the tokenizer function, the return value is an array of tokens. The second function is the parser function, the return value is a tree representing the syntax (AST). Esprima does not provide a tree traversal function, a code generator, or any other tools not related to parsing.
Esprima is a standard-compliant, high performance ECMAScript parser written in ECMAScript.
Eclipse Orion has been using Esprima as the back-end for its Content Assist. It makes sense to join the effort and make Eclipse Orion as the ultimate home for Esprima.
The current code is licensed under 2-clause BSD license.
The current master branch is quite stable. It can be released at any time. Currently it is targeted to carry the version number of 2.0.
In next 12 months, the majority of the work involves adding support for ECMAScript 6, starting from features which are more stable and less likely going to change dramatically while ECMAScript 6 specification is being finalized.