-additive blending enabled for all explosion effects (makes the explosions NOT look terrible)
-enabled FSAA by default (I mean, come on, end of 2015)
-enabled new mantle (smooth climbing)
-enabled buffer limit (reduce lag)
-made autosaves and quicksaves NOT overwrite one another (reduces chances of people who forget to save losing progress)
-enabled subtitles, fogging and weather effects (may be required by mods or fan missions)
-made sure all cutscenes are scaled properly

no mods are included in any patch, you will always need to get those separately, see the FAQ.

yeah, changed some useful things, but the new settings will probably crash my notebook if not make it lag like hell. i really don't care about full-on unnecessary AA effects in my retro games. do that for CoD or BoyFriend games if they ever come to GOG. stay away from old skool shooter/hybrid games.

i wished these "unofficial" people stop being so overzealous and playtested their patches. not re-downloading it. good mind to type up a complaint to gog's staff just for them to ignore it. meh.

I will second that I would wish unofficial patches to be optional.

you do realize that it's the same patch that made the GOG release possible, right?

as you may have noticed, there has been a NewDark release, so the current version is 2.45, therefore;

SS2 update 2.45

will fit both GOG and steam installs. as always, GOG and steam are free to incorporate it into their builds. same stuff as before:

-additive blending enabled for all explosion effects (makes the explosions NOT look terrible)
-enabled FSAA by default (smooth edges)
-enabled new mantle (smooth climbing)
-enabled buffer limit (reduce lag)
-made autosaves and quicksaves NOT overwrite one another (reduces chances of people who forget to save losing progress)
-enabled subtitles, fogging and weather effects (may be required by mods or fan missions)
-made sure all cutscenes are scaled properly

plus
-added one dml that makes sure the "reach Rickenbacker" quest completes properly (dml fixing is usually SS2tool exclusive, but made an exception for this one, as broken quests are a big no-no)
-removed the DataPermMods quick modfolder (as this is now a sureproof way of busting your SS2 install - you will have to get the modmanager or SS2tool to mod the game safely)

System Shock 2

Changelog for update Patch 2.45 ND (GOG-11) (added 04 April 2016):

- additive blending enabled for all explosion effects (makes the explosions NOT look terrible)
- enabled FSAA by default (smooth edges)
- enabled new mantle (smooth climbing)
- enabled buffer limit (reduce lag)
- made autosaves and quicksaves NOT overwrite one another (reduces chances of people who forget to save losing progress)
- enabled subtitles, fogging and weather effects (may be required by mods or fan missions)
made sure all cutscenes are scaled properly
- added one dml that makes sure the "reach Rickenbacker" quest completes properly (dml fixing is usually SS2tool exclusive, but made an exception for this one, as broken quests are a big no-no)
- removed the DataPermMods quick modfolder (as this is now a sureproof way of busting your SS2 install - you will have to get the modmanager or SS2tool to mod the game safely)

These are some excellent new features! Might warrant another reinstall :)

System Shock [Demo]

Changelog for Patch #1/ GOG-4 (Windows) (added 11 July 2016):

New Things
- Texture filtering has been applied. The textures around the station will appear smoother and less pixelated. Let us know what you think about this change as we would like your feedback on it.
- Visual effects have been improved and as well the addition of explosion visual and sound effects.
- Fragmentation grenades can now be thrown by the player. Right-click on the grenade from your inventory to throw or assign it to the hotbar and throw with the press of 1, 2, 3 or 4 on the keyboard.
- “Staminup” patches, “BeserkBooster” patches, and Battery packs can now be used by the player by right-clicking on them in the inventory.
- New melee attacks animations have been added. The Hacker will recoil when hitting a surface with the pipe.

Fixes
- Reduced the swing delay of the pipe.
- Shortened pickup animations.
- Music alterations applied to the backing music around the station.
- Fixed a bug with game settings causing controls to lock when reloading the game.
- Item descriptions have been improved for the items around the demo.
- Various performance improvements.

System Shock [Demo]

Changelog for Update / GOG-1 (Linux) (added 19 July 2016):

added the Linux version of the System Shock Demo.

Has System Shock 2 been updated recently? I'm noticing a number of differences on my current playthrough than my last one sometime late last year.

Disruption grenades are doing way more damage and nearly one-shotting Rumblers on Impossible (with 6 levels in heavy, both modifications and the sharpshooter upgrade). This might be from sharpshooter which I don't usually get but I don't think it is.

There wasn't a Wormheart implant on the first corpse in Body of The Many, nor anywhere that I could find. I don't think the Greater Psi Reaver dropped a Greater Psi Reaver organ, but it may have just been lost in the mess.

The unbreakable weapons now break; Shotgun from Med/Sci as well as the Assault and EMP Rifles from the Med/Sci Sub-Armory and I think the special pistols in Engineering have now been made normal.

And for whatever reason, the Gamma change in Options isn't working at all. I'm not sure if the game is stuck on its darkest setting, but moving the slider changes nothing and a few areas are so dark it's impossible to see (egg and spider rooms in BoTM and some areas of cargo bay).

This is the vanilla version straight from GoG, although my current version was downloaded through Galaxy. My last run in late 2016 should have been on the exact same version (unless this was quietly updated?) and I didn't notice any of these differences then, nor any differences from 2015.

I tried a Verify/Repair from Galaxy and it did update 106 MB's for whatever reason, but the Med/Sci Shotgun still breaks and the Gamma still doesn't change, so I'm not sure what needed to be changed.

Any ideas? I think there may have been a few other small item changes/removals as well, but not enough for me to notice offhand or think it was anything more than my imagination.

so you are basically complaining that bugs and issues have been fixed. well.. lets just go through everything;

-yes, because that's what disruption grenades are supposed to be doing, considering their cost, scarcity and description.
-no wormheart implants have been removed or added. while there are some scattered around the level, I'm very sure that there never was one on the first corpse.
-the greater reaver organ is broken (can actually glitch the ui out if researched) and does nothing, so the greater reaver now drops a normal reaver organ.
-gamma slider is greatly dependent on your gpu drivers, and may not work at all times, especially on intel. also, make sure you are not running borderless windowed, as the slider can only work in fullscreen.
-yes, the rogue prop that was making some weapons unbreakable has been removed. the amount of recoil (which does indeed vary) has been left alone.

see the full changelog here.

I was just listing differences and wasn't aware it had been updated.

that's why I've linked the full log.

I'm also fully open to suggestions for future fixes and tweaks - for example, it would be quite easy to add a muzzle flash to the shotgun.

Wow, it's impressive that the game is still being worked on so actively :)
I haven't played the System Shocks, yet, but I'm planning to do so sometime this year. I'm always trying to play older games as close as possible to how they were originally, except for maybe fixes to some game-breaking bugs. I'm especially trying to have them look the way they did upon release. From reading over some of these changelogs, it seems that a lot of work has gone into changing several aspects of the game as well as the graphics. So, I'm wondering, can SS2 still be made to look the way it did originally (e.g. disabling texture filtering, retouched effects, etc.)? Also, has the game been changed fundamentally, or have only minor quirks and obvious bugs been ironed out? In other words, has the gameplay experience been changed with these patches?

Thanks :)

[edit]
I just stumbled upon this thread by ZFR with the same question and an extensive answer from a year ago. So, from what I understand, playing the current GOG version of System Shock 2 is indeed different from the original, but mostly just fixes what is broken and improves graphics in a way that doesn't change the asthethics in any way. Moreover, unexpectedly, it seems like the SCP and SHTUP mods are actually really sensible choices even for someone like me. I'll definitely keep those in mind for when I'm done with SS1.

Unless any of that has changed in the past year I consider my question answered :)

GOG version is basically the new engine plus bugfixes. no graphics changes, no retouched effects or anything like that - it's as vanilla as it gets without a retro computer.