Rick Hightower

Interview...with Mike Cowlishaw
Creator of NetRexx

R. Hightower: Have you considered an open- source license?
M. Cowlishaw: Until recently the licensing issues seemed something of a minefield with so many different ideas on what open source should be. Also, my translator/compiler is very much a research scaffolding (for example, it has hooks, which look like dead code, for multiple input syntaxes). At the moment I'm (finally) implementing the interpreter pathways, which is very much a work in progress; this sort of thing is much easier to do when only one person is working on the code as a whole.

RH: Are there any plans to do a VisualAge for NetRexx?
MC: You should probably ask the VisualAge people. I've shown screenshots of VisualAge running NetRexx - since it's pure Java underneath, all the debugging mechanisms work just fine. Classes generated by NetRexx should run fine under VAJava.

RH: How many people subscribe to your NetRexx mailing list?
MC: To be honest, I don't know. It's run by folks in a data center in the south of England, and I don't have admin privileges on it. It must be many hundreds, though - when I put out 1.160 last week there were several hundred downloads within a day, and it was announced only on the mailing list.

RH: Where do you see NetRexx going in the next five years?
MC: I see it continuing to show the value of clean syntax, etc. It currently ships with the VM/ESA operating system and I hope to see it ship with other operating systems and implementations, too.

RH: Is the use of NetRexx on the rise or decline?
MC: Rising as far as I can tell. The Java platform has only really been accepted this year for "mission-critical" work now Y2K is over, and the shops that are starting to use it often have a long REXX or PL/I heritage, so they're "natural" NetRexx users.

RH: Is the use of REXX and Object REXX on the rise or decline?
MC: I've lumped these together, as Object REXX is upwards compatible with "classic" REXX, so new sales (especially on PCs and workstations) are all Object REXX. On the whole, "classic" REXX usage is flat, except on the MVS (OS/390) platform, where it's increasing (in most cases, REXX is built into the operating system). ORexx is growing, especially on Windows and *X (perhaps as people move from OS/2, etc.).

RH: How many people are working on NetRexx?
MC: In IBM, on the reference implementation, it's just me. There are other people working on other implementations. Lots of people outside IBM contribute ideas and code not directly concerned with the compiler - Dion Gillard, for example, is building a NetRexx IDE which should be good....

RH: How important does IBM view REXX? NetRexx? Object REXX?
MC: There's a permanent development group for REXX products, based in Boeblingen, Germany. They produce and maintain all the classic REXX interpreters and compiler, and also Object REXX. REXX products are a multimillion-dollar business - there are huge amounts of code written in REXX.

RH: Is there a good debugger for NetRexx?
MC: NetRexx classes are Java classes, so any Java debugger can be used with NetRexx classes. By default (unless you specify format), line numbers are correct too, due to a "cunning trick." So any debugger that correctly picks up the source file name from the .class file should work fine. I tend not to use debuggers, so I can't really advise much on this one.