[Postosuchus]

Speaking of crazy applications of Emacs... Long long time ago, my team was tasked with rebuilding an MBS analytics system for one of the leading fintech companies. The original system ran on DEC VAX and was written in VMS Pascal (let's just say, a very unique flavor of Pascal). Rewriting it from scratch was not an option (it would take decades to implement all that complexity and to make sure it worked correctly). Instead, we utilized a combination of tools that first transformed the Pascal code into the form that was closer to more popular Pascal dialects (which included using a Scheme compiler and (drum roll) Emacs in batch mode), applied a set of hand-made patches, translated into C using p2c, and finally built on Linux. As crazy as it sounds, it worked well enough to be used as a foundation for the next gen of mortgage analytics.

[usrnm]

Once it's just regular Pascal, why translate it to C? Why not just keep it as is and compile with Free Pascal/Lazarus?

[p_l]

Depending on the time frame, FreePascal/Lazarus might have simply been not available (or unknown) to the team.

I remember how in ~1997 at a science camp we used Turbo Pascal under DOS for most programming labs, and whenever pascal code was run on Linux machines we used p2c translator and compiled the resulting C code.

[Sharlin]

Free Pascal’s initial release was in 1997. "Long long time ago" may be longer than that.

[jdboyd]

Sounds like a story that should be submitted to the above linked website!

[TheBlight]

TIL people were concerned with mortgage quality prior to 2008.

[actionfromafar]

I am slightly disappointed that the solution was not to run a VAX emulator. :)

[Postosuchus]

I don't think VAX emulators were the thing back then. :-) In fact, our target platform was a cluster of commodity DEC Alpha machines running an early version of RedHat Linux for AXP. I know for a fact, that we were the first system that employed Linux clusters in fintech.

[ggm]

They weren't but .. if you were doing it now QEMU and OpenVMS would probably be the natural approach.

[0x445442]

This is what Ticketmaster did. Up until a few years ago, and it’s probably still the case, they heart of their reservation system was written for the VAX in the 70’s. When they had to make the hardware/OS switch, rather than port, the went to an emulator.

Edit: spelling

[nightowl_games]

Decades? Seriously?

[Postosuchus]

Yes, absolutely. You will be shocked how complex CMOs might be just to calculate plain cashflow on a tranche (https://www.amazon.com/Handbook-Mortgage-Backed-Securities-7... is a great standard treatise on the topic). Add to this interest rate modeling and prepayment modeling - and we are talking serious logical complexity. And this is the area where people get REALLY pissed when you have bugs.

[ggm]

If the bugs affect your shock preparedness, and liquidity status and mandated holdings/reserves, you might be in a world of hurt: Failing compliance can permit the feds to step in and seize the enterprise, if it's in the regulated space.