Neko is a high-level dynamically typed programming language which can also be used as an embedded scripting language. It has been designed to provide a common run-time for several different languages. Neko is not only very easy to learn and use, but also has the flexibility of being able to extend the language with C libraries. You can even write generators from your own language to Neko and then use the Neko run-time to compile, run, and access existing libraries. If you need to add a scripting language to your application, Neko provides one of the best trade-offs available between simplicity, extensibility and speed. Neko allows the language designer to focus on design whilst reusing a fast and well constructed run-time, as well as existing libraries for accessing file system, network, databases, XML... Neko has a compiler and virtual machine. The Virtual Machine is both very lightweight and extremely well optimized so that it can run very quickly. The VM can be easily embedded into any application and your libraries are directly accessible using the C foreign function interface. The compiler converts a source .neko file into a byte-code .n file that can be executed with the Virtual Machine. Although the compiler is written in Neko itself, it is still very fast. You can use the compiler as standalone command-line executable separated from the VM, or as a Neko library to perform compile-and-run for interactive languages.