Growing article, with links to many related topics. [Wikipedia]

OO language based on, integrated with, Java (compiler emits Java bytecode); features of functional programming, implements state-of-art results from academic research, for more expressivity, modularity, safety. [Open source, GPL]

Interactive geomatic object-oriented language for spatial modeling, image processing, remote sensing, digital photogrammetry, geographic information system (GIS), geodesy, and surveying and mapping.

High level, simple, Java-style, object-oriented, compile time error checking; native support for major concepts of time, state, properties, networking, which few languages address, to greatly simplify code. Mainly for games.

Experimental, innovative, object-oriented, interpreted language, and programming environment LavaPE; edits programs via syntax-sensitive point-and-click style structure editors, not text editors; parameterized (virtual) types, refactoring, static checks.

Dynamically compiled, object-oriented language and environment, especially suited for web applications.

Multiply-polymorphic modular language with highly flexible syntax. Unique inheritance model allows multiple inheritance and polymorphism, constrained genericity, covariant attributes via immutability. Due to identityless nature of types, a type can ha...

Makes paxScript: general purpose, imperative, object-oriented language, with new technology of dynamic data structure processing; lets one process dynamic data structures (lists, trees, more) effectively with no pointers. Ensures laconic and uniform n...

Practical OO language: Ruby-like expressiveness with Haskell-like static type checks. Coded in ML, runs on Linux. [Open Source, GPL]

Syntax similar to C++, Java, advanced high level features: strong type system, automatic memory management, global code optimization. Development website, has some documentation, forum, announcement from developers, sources. [Open source, GPL]