I used the included glwarp.exe and it played back fine. Thanks. 

You said you'd be watching demos. Requiem does have some sort of demo rewind and fast forward because it based off JoeQuake.

I would imagine Warpspasm 100% demos would be rather long. 

Yes it was purely for watching the demos parubaru mentioned. Before downloading Requiem I thought I'd try the engine mods included with the map pack. glwarp.exe played them back fine, albeit without the rewind/fast-forward functionality as you said. At least the demo was a 100% run and quite fun to watch.

Speaking of demos, the only playback functions I'm aware of with vanilla Quake/Quakespasm/FitzQuake is play and pause. Are there any others? Googling turned up nothing. 

Vanilla Quake/Quakespasm/DarkPlaces that is really all you can do, although you can fast forward with host_framerate. Rewind is simply impossible, rewind ability in an engine requires a fair bit of work.

Mark V has demo rewind/fast forward better than JoeQuake with the arrow keys. Press tab (+showscores shows how much of the demo remains to be played.) qbism super8 (a WinQuake style engine) also has demo rewind based on the Mark V style implementation.

glwarp is a neat engine for its time. One upon a time was only huge maps engine with classic look. 

Thanks!
Do I just drop any of the mark_v exes into my Quake directory?
And speaking of engines, what's the best way to run Nehahra nowadays? Quakespasm + Spirit repack from Quaddicted? 

The best way to run Nehahra is probably still with one of the original engines built especially for it. Nehahra is a bit of a special case, and a lot of what it does (and the way it does it) dates from a time before things were really well standardized. Consequently, Nehahra tends to do many things in a way that's not really compatible with everything else (and some are outright broken, like adding extra protocol functionality without changing the protocol version). Even DarkPlaces gave up on maintaining Nehahra compatibility a long time ago. 

@maiden - Mark V runs Nehahra (put this in the nehahra dir fmod.dll. Add -game nehahra -nehahra to the command line.

Engines that can play Nehahra: Mark V, JoeQuake, Requiem, engines that come in the zip if they still run.

Do "nomonsters 1" to stop the annoying strafe if you want.

@mh -- Hehehe. You ought to see how nice Mark V runs Nehahra or Zerstorer. Both mods like to screw up your settings really badly when playing cutscenes or Nehahra playing between level demos. They mess with your crosshair, wateralpha, fov, viewsize. Mark V treats those as "display hints" instead, your settings remain unchanged. 

I found that the 'best' way to run Nehahra
depended some on the hardware, graphics card etc.

Three computers, three engines. The orinigal ones are worth a try, and I seem to recall on one machine I eventually went with nehwarp (an engine in this release).

Most currently I used a very recent markv, which was updated to support the Nehahra fog system. I think you can just drop the markv files into the Quake directory, yes.

I set cl_autodemo 0 in the config, and recommend the command: cutscene 0. Launch with the command: markv -nehahra -game nehahra for the fog. Apart, from the initial stutter upon launch I had no problems with the pack. 

Thanks for the feedback, much appreciated. So no Quakespasm for Nehahra? I recently ran Zerstorer with a recent build of QS (0.92 I think) and didn't notice any issues. Just wondering. 

QuakeSpasm doesn't have any of the Nehahra-specific engine features, so it's best not to use it for Nehahra. The maps load but various stuff will be broken (I'm not sure to what extent).

Zerstorer on the other hand, I think runs on any Quake engine (I remember playing it on Winquake when I didn't have a gpu.) 

I just did c:/quake/quakespasm.exe -game nehahra -nehahra -->Single Player->New Game and it did a Quake Error "sprites/explode1.spr" has wrong version number, should be 32".

Plus Nehahra requires some qc functions that aren't in original Quake like PF_changepitch, PF_sqrt.

(Also the progs.dat with just certain maps like to crash Quakespasm if you remove the sprite32s. Quakespasm Spiked ironically has a fix for that.)

For completeness, the wrong menu shows (it shows, I guess the "Seal of Nehahra" menu instead of the game menu --- Nehahra's actual menu is named differently), the fmod .xm music won't play, Nehahra needs some extra cvars available or it won't work right (which I think is limited to cutscenes). Plus Nehahra does not use what we view as the normal "fog" worldspawn entity, it rolls it own way via an svc. Nehahra also has some custom effects (certain particle numbers it treats differently).

Even with a non-Mark V engine that properly supports Nehahra --- all kinds of stuff likes to mess with your settings during the course of gameplay. You might have a certain fov or crosshair you like, perhaps a certain r_wateralpha setting --- and Nehahra will smash your config to pieces.

(Zerstorer likes to do some of that as well. If you use Quake default settings, someone may not notice --- like fov 90, viewsize 100, r_wateralpha 1, crosshair 0 -- you may never know it happens).

Nehahra is difficult to deal with.

mh wrote a long commentary about Nehahra once. It was a good read.

I got obsessed a bit with Nehahra, pushed my stack of engine coding chip into the pot and said "All In" a few years ago and kept defanging it until I could play it and enjoy it with zero annoyances.

(Then I think I stopped engine coding for 2 weeks and played Nehahra with some frequency -- -haha. Nehahra really is quite a masterpiece and it becomes clear after the annoyances are eradicated). 

Recorded a playthrough on "+Quoth Nightmare", i.e. "skill 3; coop 2". A while ago actually, but youtube was being fussy. In 4k or as demos.

IMO that the coop flag makes this masterpiece even more masterpiecey. Gugs and droles are less exploitable and a fairer challenge (esp. in ambushes) than shamblers, extra deathlords make ammo management a bit tougher, and I prefer gaunts to vores as well. Vorelings don't work as tarbaby replacements at all though.
It isn't fully coop-compatible: GL secret in warpa softlocks warpb, and half of warpd can be skipped by picking up the same keycard multiple times.
Other than that, what's there to say? It's still the best.