The Realtime Programming Language (RPL) is a compiled programming language that was used on machines running the Pick Operating System. From 1974 to 1978, the Microdata Reality from Microdata Corporation of Irvine, California, was the only machine running this operating system. However, in 1979, Ultimate Corp, a former Reality vendor, developed their own system. Either Ultimate or SMI implemented RPL on all or some of their machines as well. It's possible that SMI did the implementation on the Ultimate machines since users were allowed to load their own ABS frames (assembler) provided they took responsibility for the results.
All Pick Operating System machines come loaded with the PROC language which is a procedural language (not unlike a Windows or Unix shell script), and also with the BATCH/UPDATE processor which enabled file manipulation. However, the PROC language was extended first by Virtual Data Services of San Diego, California in 1974. They called their extended version PORC which stood for Processor Oriented Reality Control Language.
At the time that PROC / BATCH / UPDATE and later PORC were developed, there was no other programming language available for the Pick Operating System. In 1974, or shortly afterward, Ken Simms, then working for Pick and Associates, wrote the first compiler for the Pick Operating System, which was called SBASIC. This compiled language was expanded more and eventually renamed Data/BASIC which today is called just Pick BASIC.
The PROC / PORC language was extended further into the 1970s by Tim Holland, then working for SMI (Systems Management, Inc), a company based in the Chicago area, in the town of DesPlaines. SMI had also been Microdata's largest dealer, but when Pick demonstrated the new BASIC language, they balked and further developed PORC, which they named SMI Extension Language or SMILE and eventually renamed RPL. Some believe RPL stands for Realtime Programming Language, however I think the original name might have been Reality Programming Language. Of course, once they began implementing it on other machines, they could no longer call it Reality.
Data/BASIC was developed by Nov 1975, by which time however, complete systems had already been written in PORC / SMILE which were sold mainly in the Chicago area where SMI was based. Some of the developments of this language were coded back into the Microdata REALITY and termed PQN standing for New PROC. Since later vendors had to be able to shift code into their systems, PQN came to exist in all Pick implementations. It is however only a light version of RPL.
As for BATCH/UPDATE, once BASIC was developed, most of the BATCH/UPDATE processor routines, were re-written in BASIC since the BATCH/UPDATE processor was very difficult to understand, while BASIC was much clearer, and being taught in schools. BATCH/UPDATE however continued to be documented, shipped and used well into the 1980s.
By the way, the name below which some Wikipedian has decided was Paul Desjardine, should actually be Paul Desjardins.
The below text copied on 7 Feb 2011 from the article at Wikipedia version last update 10 Mar 2010
PORC Manual dated Jun 1974 (PDF)