When comparing Source vs Amethyst, the Slant community recommends Amethyst for most people. In the question“What are the best 3D game engines?” Amethyst is ranked 26th while Source is ranked 29th. The most important reason people chose Amethyst is:
Amethyst is published under the MIT license making it open-source and id offered completely free. This allows anyone to give the tiling window manger a try, which is great.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Great documentation
Valve's official documentation website is great for newbies. It demonstrates the pros and cons of the engine (and since the website isn't maintained by Valve, but instead the community, the pros and cons are largely unbiased). There are also a number of pages dedicated to entities used within official Valve games and also community-made mods that were turned into full-fledged games by Valve. These pages explain the ins and outs of how most source programming works. There are also guides for Valve's tools which are both included in Source SDK and in any Valve-developed game.
Pro Runs on every potato pc
Since it has precalculated lighting, this engine is great for low end PCs too.
Pro Many basic entities
You don't need to code your own door or ladder etc. You can pretty much use every entity used in Half-Life 2 yourself easily.
Pro Visual logic, no programming
Of course you can program stuff into source but for level design only, source has a really easy input/output system for your level logic (e.g. doors, trigger when player walks into room...).
Pro Has a built-in video capture and editing application
Source includes Source Filmmaker, a video capture and editing application.
Pro Easy way to export or load source models to unity and maps
Pro It's free and open-source
Amethyst is published under the MIT license making it open-source and id offered completely free. This allows anyone to give the tiling window manger a try, which is great.
Pro Recently updated and rewritten in Swift.
The application was written in Objective-C, but was recently updated and completely rewritten in Apple's new native language Swift.
Pro Works with keyboard shortcuts, no mouse needed
As it's designed to work closely to how xmonad, Amethyst uses keyboard shortcuts to control the windows being used, meaning no mouse input is necessary. This can make for a faster way to control windows.
Pro Multi-monitor suppport
Pro Has many common layouts to choose from (fullscreen, floating, row, column, wide, etc)
Pro Can switch between tiling and floating mode
Pro Under active development
Pro Configured via UI
No CONFIG file provides security and will avoid making amethyst crash. Instead configured via simple UI
Pro True tiling means never losing track of windows under a huge pile of others
Cons
Con Only for mods
Normally, you can only use the Source Engine to develop "source-mods" (as Steam calls them), however the developer wiki is correct in saying Valve have a proven track-record for finding source-mods and turning them into fully-fledged games, Black Mesa Source is a good example of this, as it began life as a source-mod available for free, however Valve turned it into a fully-fledged and paid game.
Con SDK is outdated and difficult to use
Source SDK has not been updated in ages, and has instead been "re-released" under different names, e.g "Source SDK 2013 Singleplayer".
It's honestly easier to use the version of SDK included with any Source game, namely Portal 2 or DOTA 2, since both have a variant of Source SDK that is more updated than anything you can find in the tools section of Steam.
Con Can be buggy at times
Con There are more user friendly window managers available
There are certainly more user friendly window managers available for MacOS, such as Divvy or Moom. Amethyst, however, is more powerful and customizable than the more user friendly options available and therefore may be a better choice for a user looking for more advanced capabilities and customization.