Slang is a proprietory language developed by GS, it's been around for ~15 years I think. If I remember correctly they have a development/analysis environment called SecDB in which all coding is done with Slang. All their modelling, pricing and risking is done in SecDB across all asset classes so it's pretty widely embedded.
I've looked at Slang a bit. It's an interpreted dataflow language running on an in-memory database called SecDB. Untyped, Pascal-ish, single-threaded, and poor support for namespaces. Like a spreadsheet, it only needs to recompute the subgraph that has changed. It was probably innovative 25 years ago (I think it came out mid-80s), but today you could write Java code and use memoization aggressively to speed things up. Slang is not why GS traders are successful. AFAIK, GS succeeds because they listen to their risk people.
A former GS pricing quant describes Slang briefly in a footnote at the following URL. It doesn't go into much detail, but maybe adds a morsel to what's been mentioned:
"Like a spreadsheet, it only needs to recompute the subgraph that has changed."
Yes that's right - and that is a key feature for GS - they need to be able to revalue huge trading books ~ real time. (Most other banks estimate impact of intraday moves, and do a re-price overnight in batch)
Didn't GS have a losing second quarter? Perhaps this spin-off has more to do with how they perceive the next quarter is going too, and worries about business beyond that.
By embedding so much info company wide in SecDB aren't their risk people in a better position to make their case?
Still, that wouldn't matter if GS wasn't inclined to listen to them, but the whole Slang/SecDB system is indicative of a company culture that's serious about these sorts of things.
