interp is a powerful programming language, a testing platform, and a development framework. It is targeted for Linux/Unix-based systems, yet remains adaptable to less powerful embedded systems that were never intended to host an interactive programming language, because all you need is a serial port. I2 is a compiler for interp.
Funky is a tiny, embeddable programming language with almost unlimited extending capabilities. It presents itself as a single class that contains the entire interpreter. Two versions of this class exist: Funky::Funky, a floating-point version, and Funky::Groovy, an integer version. You can install your own functions in the language as long as your functions take a vector of the built-in type of the interpreter and return an instance of that built-in type (or a vector of those). Funky is a functional programming language. As such, it treats everything as functions, and those functions handle only one type: double in the case of Funky::Funky, or int in the case of Funky::Groovy.
The Virgil Programming Language is designed for building robust, flexible, and scalable software systems on embedded hardware platforms such as microcontrollers. Virgil builds on ideas from object-oriented, statically typed languages like Java, providing a clean, consistent source language. Its compiler system provides an efficient implementation for resource-constrained environments.
SPL is a powerful scripting language. It features hashes, regular expressions, objects, exceptions, a built-in template language, and has a C-style syntax. It can be used stand-alone or embedded in other applications. The entire SPL toolchain (compiler, assembler, virtual machine, etc.) is pretty small (about 100k on x86 architectures). One of the more advanced VM features is the capability to dump the entire VM state to a file and resume later. It even is possible to resume on another machine with a different architecture.
The MetaC programming language is a 100% backward compatible extension to the C language that adds reflections and the ability to analyze and modify C source code at compile time. It has been specially designed to search for arbitrary code structures and instantiate new source code. Typical applications for MetaC based meta-programs are development tasks concerning embedded and real-time software. Examples are API abstraction and retargeting to a new API (ever been locked to a vendor-specific API?), application specific debugging and profiling on an embedded target, and WCET measurements.
Neko is a high-level dynamically typed programming language. It can be used as an embedded scripting language. It has been designed to provide a common runtime for several different languages. Learning and using Neko is very easy. You can easily extend the language with C libraries. You can also write generators from your own language to Neko and then use the Neko Runtime to compile, run, and access existing libraries. Neko is a good way for language designers to focus on design and reuse a fast and well-designed runtime, as well as existing libraries for accessing filesystem, network, databases, XML, etc. It has a compiler and a virtual machine. The virtual machine is very lightweight and well optimized. The VM can be easily embedded into any application, and your libraries can be accessed using the C foreign function interface.
The Hecl Programming Language is a high-level scripting language implemented in Java. It is intended to be small, extensible, extremely flexible, and easy to learn and use. It is intended as a complement to the Java programming language, not a replacement. As such, it tries to do well what Java doesn't, and leaves those tasks to Java for which it is best suited. It is also easy to add Hecl to Java, or write new Hecl commands in Java. It aims to be a very immediate language so that you can pick it up and start doing useful things with it quickly. Of particular interest is the fact that it's small enough to run on Java-enabled cell phones, so you can quickly script applications for them!