Considering our limited human resources and time constraints, it is hard to give definitive and accurate estimates of the milestones we are going to release.

Tentative Roadmap

Groovy 1.7.x

Releases

• incremental bug fix releases through 2010

Groovy 1.8.x

Feature set

Here are a few topics we're considering for Groovy 1.8 and beyond.

• internal runtime optimization
• extended command expression (GEP-3)
• extended annotations (closures, lists, maps, ranges)
• support for joint compilation of AST transformations
• modularity of Groovy (splitting Groovy in smaller JARs on a per feature basis)
• work related to JDK 7
  • usage of invokedynamic and annonymous classloader (JDK7 features)
  • updates for JDK 7 language features (aka Project Coin)
  • retrofitting Groovy closures to accomodate JDK 7 upcoming closures for interoperability
• a native template engine compiling to AST (faster, correct line numbers for error reporting, optimized outputting, etc.)
• experiments
  • with pattern matching (to be started as a module)
  • with parser combinators (to be started as module)

Releases

• Groovy 1.8-beta-1: March 2010
• Groovy 1.8-beta-2: May 2010
• Groovy 1.8-beta-3: July 2010
• Groovy 1.8-RC-1: mid-September 2010
• Groovy 1.8-RC-2: end of September 2010
• Groovy 1.8 GA: October 2010

Groovy 2.0

Feature set

• New Meta-Object Protocol
• Incremental compiler

Other topics we could consider for Groovy 1.8, 2.0 and beyond

• ability to pass expression trees / AST nodes as parameters (see C# 4's own expression tree)
• lexical categories
• a symbol concept, a bit like Ruby's :symbol, or like Java interned strings
• co-routines and/or generators
• tail-call recursion