99 Bottles of Beer on the Wall: Limbo version.
A Descent into Limbo: Article by Brian W. Kernighan.
An Analysis of Inferno and Limbo: By Kim Nyberg. Paper presents, discusses, compares Inferno network OS and its Limbo language: history, precedents, motives, goals, main features; similarities, differences to Java OS, Java. Bibliography. Helsinki University of Technology.
Limbo 2.0 SDK References: Language basics, programming guide and language definition.
Limbo Manual: Language definition (January 1997).
Programming in Limbo: In BYTE Magazine, sec. Core Technologies.