Scheme Programming/A Note on R5RS< Scheme Programming
As of 2012, the current standard for Scheme is R6RS, yet most implementations of Scheme today still only implement the old standard R5RS. RnRS, in general, stands for "Revisedn Report on the Algorithmic Language Scheme," a nod to an influential document with a similar name, the "Revised Report on the Algorithmic Language Algol 60." The current standard, R6RS, elicited controversy among some Scheme programmers who criticized its departure from Scheme's original minimalist philosophy. Development of a new Scheme standard is currently underway; the new standard will include both a simple subset of the full language intended to please hobbyists and educators and a larger language for professional programming.