Limbo is a programming language created by Bell Labs in the early 1990s. It was designed to be a simple, easy-to-use language that would make it easy for non-programmers to create programs. Limbo was also designed to be very portable, so that programs written in it could be easily moved to different platforms.
Limbo is a procedural language, which means that programs are written as a sequence of instructions. Limbo has a small set of built-in data types, including integers, strings, and Booleans. Limbo also supports user-defined data types.
Limbo is not a particularly popular language, but it has been used in a few notable projects. One is the Plan 9 operating system, which was developed by Bell Labs. Plan 9 uses Limbo for its user interface. Another is the Inferno operating system, which was developed by Lucent Technologies. Inferno is used in a number of embedded systems, such as cell phones and routers.
If you're interested in learning Limbo, there are a few resources available. The book "Limbo Programming" by John Ousterhout is a good place to start. The Plan 9 operating system also comes with a tutorial.