There are some changes to vanilla Arx Fatalis installation, but done only to improve the game in the way developers would do had they continue to support it.

I´d say don´t even play without it, it seems to put away some pesky bugs and make some thing more easily recognizable.

For a full list of changes, see this.

Any idea when version 1.2 will be released? It's been a couple of years.

Okay, I've downloaded a snapshot of the latest dev build from the Wiki. How do I install it? Do I have to compile or just drag and drop the files to the folder?

If you want to build from source this page should be helpful:
wiki.arx-libertatis.org/Downloading_and_Compiling_under_Windows

If you need further help feel free to join our irc channel.
wiki.arx-libertatis.org/IRC_channel

EDIT:
Sorry for not using proper links, the forum software would not let me.

Thanks! I'll try compiling it (I'm fairly new to this). Is the latest master fairly stable and bug-free?

We have a category on the bug tracker containing things we know got worse:
bugs.arx-libertatis.org/arx/issues/find/saved_search/6/search/1

More testing of master would be greatly appreciated.

Great news, Am Shaegar(s)!

You can now download snapshot versions of Arx Libertatis. This means you can take advantage of the past two years' improvements since 1.1.2 came out, by downloading 1.2 in progress. Link: http://arx-libertatis.org/files/snapshots/

On Windows, just unzip the folder and make sure to put the necessary Arx data files in there or in the Save folder- it should then work out of the box.

This was a nice relief after I had trouble compiling it myself. I found the latest master builds to be 99% fine, but there are a few known regressions: https://bugs.arx-libertatis.org/arx/issues/find/saved_search/6/search/1

There's no reason not to use these instead of 1.1.2 right now! If you find any issues make sure to report them on the bug tracker above and/or on the IRC channel .

I have a bug with the teleporter on Level 3. When I activate it, I see the white cone in the middle of the circle on the floor but the gates that you need to activate to teleport don't show up so this teleporter can't be used. Any idea how to fix this?

What version of Arx Libertatis did you try? If this still happens with the latest development snapshot from http://arx-libertatis.org/files/snapshots/, please file a bug report at https://bugs.arx-libertatis.org/ and attach a save file.

Here is a New 64 bit version of Arx Liberatis 1.1.2 http://www.moddb.com/mods/arx-libertatis/downloads/arx-libertatis-112-windows-installer-64-bit

Praise Akbaa, the project is not dead!

Arx Libertatis is available on GOG? Where?

Why would it be available on GOG? It's source port of Arx Fatalis made by fans and requires the base game to run. You download it from Arx Libertatis website.