Limbo (programming language)

Infobox programming language
name = Limbo

paradigm = Concurrent
year = 1995
designer = Sean Dorward, Phil Winterbottom, Rob Pike
developer = Bell Labs / Vita Nuova Holdings
latest_release_version =
latest_release_date =
typing = Strong
implementations = Dis virtual machine
dialects =
influenced_by = C, Pascal, CSP, Alef, Newsqueak
influenced = Stackless Python
operating_system = Inferno
license = Open source
website = [http://www.vitanuova.com/inferno/limbo.html http://www.vitanuova.com/inferno/limbo.html]

Limbo is a programming language for writing distributed systems and is the language used to write applications for the Inferno operating system. It was designed at Bell Labs by Sean Dorward, Phil Winterbottom, and Rob Pike.

The Limbo compiler generates architecture-independent object code which is then interpreted by the Dis virtual machine or compiled just before runtime to improve performance. Therefore all Limbo applications are completely portable across all Inferno platforms.

Limbo's approach to concurrency was inspired by Hoare's Communicating Sequential Processes (CSP).

Language features

Limbo supports the following features:
* modular programming
* concurrent programming
* strong type checking at compile- and run-time
* interprocess communication over typed channels
* automatic garbage collection
* simple abstract data types.

Examples

Limbo uses Pascal style definitions (minus the VAR keyword) as in:

name := type value; name0,name1 : type = value; name2,name3 : type; name2 = value;

Hello world

implement Command; include "sys.m"; sys: Sys; include "draw.m"; include "sh.m"; init(nil: ref Draw->Context, nil: list of string) { sys = load Sys Sys->PATH; sys->print("Hello World! "); }

Books

The 3rd edition of the Inferno operating system and Limbo programming language are described in the textbook "Inferno Programming with Limbo" ISBN 0470843527 (Chichester: John Wiley & Sons, 2003), by Phillip Stanley-Marbell. Another textbook "The Inferno Programming Book: An Introduction to Programming for the Inferno Distributed System", by Martin Atkins, Charles Forsyth, Rob Pike and Howard Trickey, was started, but never released.

See also

* The Inferno operating system.
* Alef - The predecessor of Limbo.
* Plan 9 from Bell Labs

External links

* [http://www.vitanuova.com/inferno/limbo.html Vita Nuova page on Limbo]
* [http://doc.cat-v.org/inferno/4th_edition/limbo_language/descent A Descent into Limbo] by Brian Kernighan
* [http://doc.cat-v.org/inferno/4th_edition/limbo_language/limbo The Limbo Programming Language] by Dennis M. Ritchie and [http://doc.cat-v.org/inferno/4th_edition/limbo_language/addendum Addendum] by Vita Nuova.
* [http://www.gemusehaken.org/ipwl/ Inferno Programming with Limbo] by Phillip Stanley-Marbell
* [http://swtch.com/~rsc/thread/ Threaded programming in the Bell Labs CSP style]