Considering that some people appear to have issues with using the Google Docs spreadsheet format or are intimidated by it, I am considering adding a quick tutorial on how to use its filtering and sorting options to make using it easier for everybody. Anyone interested by such a thing?
This thread is a continuation of the Community Mods and Plugin Library which used to be a list containing a large number of mods ordered by category to help people finding new ones. Unfortunately, it was lost in early January 2017 along with several other mod release threads with no hope of recovery. This new thread will hopefully succeed in replacing the old one, and hopefully help users finding new mods.
Big big thanks to @CarnageINC who gave be a massive help when building the library and is personally responsible for referencing a great part of the mods in the library as well as maintaining the Add-on Development Mod Library, and kudos to @nismobg for the original thread from which I stole quite a few mods and ideas.
A few notes on the structure of the library:
The library is hosted on a GoogleDocs spreadsheet. This allows you to filter and sort mods how you like, to download the library to access it offline, removes the dependency on the forums software, makes my job of updating stuff easier, and most importantly allows someone else to continue maintaining the library should I die unexpectedly.
Mods are organised by categories. Things can and will evolve as more mods are added to make it easier to find mods.
Version compatibility is taken directly from the thread titles as I won't always have the time to check every single mod. Know that mods compatible with KSP 1.5 will generally be compatible with 1.5.1 (and so on for other versions).
A "+" next to the version number means that a more recent version of the mod is available either as a patch or has been integrated into another mod.
A "*" next to the version number means that the version displayed on the library is not the same as the version the mod is updated to, usually because the mod is compatible with later versions as is.
The modders cited are the owners of the release threads, not necessarily the creators or sole developers of a mod.
I am open to suggestions: if you feel that a mod is missing, that the categories could be improved, that a mod does not fit in its current category, or know that a mod is working or not with a given version, your participation is welcome as are any ideas to improve this list.
COMMUNITY MODS AND PLUGINS LIBRARY SPREADSHEET
If you don't want to or cannot use the Google Docs spreadsheet, there is a .txt file containing all the mods in the library available at the link below. It is best viewed from an editor without automatic line-break. (It is hosted on Dropbox, if you cannot access it, I can send you the raw text via PM)
CMPL.TXT FILE (last updated 2018/11/18 YMD)
For mods that are not compatible with KSP 1.2 and later, see the Outdated Mods list in the post below.
Descriptions of the categories:
General Utility: Generally useful mods, here to improve your quality of life. A broad category.
Crew Utility: All things Kerbanauts, mods to move them around, to add new classes, to make EVAs more entertaining... are here.
Part Utility: Various small tweaks to KSP existing parts. A bit of everything in here.
VAB/SPH: Mods that make it easier to build your rockets or planes.
In-flight Utility: So that flying your missions becomes even more enjoyable. Manage your vessels, fly by moving your mouse, refuel...
In-flight Information: Real engineering takes a ton of numbers, so here you go: all the flight/atmospheric data you can ask for.
Autopilot: When doing dozens of gravity turn in a row becomes boring, or simply when you are tired to deal with the abomination that is stock SAS.
General Parts: Parts that don't really fit in the categories below. Various parts for various uses.
Themed Multi-Parts Pack: Install a few dozen parts at once! These generally come with complementary uses and uniform art style so you don't have to manage a ton of mods.
Drives, Engines and Tanks: Anything that makes your contraptions go (or crash, you decide). From basic engines to Hollywood-class absurdities, and tanks filled with explodey stuff that powers these.
Spacecraft and Station Parts: Stuff that goes and stays in space. Stations and the spacecraft to navigate from one another.
Spaceplanes and Aircraft Parts: Wings, jets, cargo bays, cockpits, propellers... Anything you'll need to dominate the atmosphere.
Ground and Naval Parts: The stuff that stays on the surface and looks up in envy to the majestic machines defeating gravity. Or that bolts through the hills or waves as fast as suspension (and terrain seams) will allow.
Weapons: Another Kerbal put its flag over that mountain, you want this mountain for yourself, if only you had more convincing arguments...
Replica Spacecraft and Launchers: Rockets and spacecraft that work in real life (or don't). Recreate your favorite missions using these mods.
Replica Parts: When you don't need the entire rocket but just an engine or so.
Bases and Resources: After a flag, plant a building into other planets. Dig holes, refine fuel, build a space centre and claim the entire planet as Kerbalkind's.
Alternative Stellar Systems: New places for new experiences. Rule of thumb: if Kerbin is not there anymore or if the Sun is not alone, it goes here.
Additional Planets: Add a few planets to the Kerbal solar system to push your interplanetary conquest even further. These mods leave Kerbin or the Sun where they are.
Planetary Structures: Cities and new space centres available for you to explore and exploit.
Career, Credits and Contract: Money money money. How to get money, how to spend money and how to get more money. New contracts for your space program to thrive and finally afford that gold-plated VAB.
Tech Tree: Reorganise the tech tree to make it more suitable to your play-style.
Science: New science experiments and instruments, and ways to manage it: unravel the mysteries of the Universe! (That sounds a bit cliché doesn't it?)
Life Support and Health: The more ways you can die, the funner it is! Look here to make your Kerbals addicted to the things we weak humans need to survive.
Realism: Mods that bring KSP one step closer to real life. New mechanics, new physics and new stuffs bringing more challenge to the game.
Visual Enhancements: Make KSP pretty (and tank your FPS at the same time). Clouds, lighting, terrain now give planets the grandeur they deserve.
Audio and Video: Various mods to make your audio and visual experience more enjoyable. These don't necessarily make the game prettier, but look here for crazy camera angles, incredible beeps, and just things that make KSP nicer to your senses.
Fashion: Flags and textures go here. Add patches for your missions, flags of your favorite country and new paint schemes for your craft.
IVA: These mods make internal view prettier, more immersive, more useful, and just overall better.
Framework: Mods that make mods work. You probably won't need these on their own but a lot of mods require them to function properly. Requirements are often packed with the mods that need them but find them here when they are not.
Modding Tools: These don't concern us lowly players but are made for the people working to make your game better. Mods that make modders work.
External Software: Here go the things that don't necessarily directly interact with KSP. Still very useful nonetheless!
Finish moving mods from the old library to the spreadsheet. DONE!
Rewrite the main topic to make the spreadsheet the main resource. DONE!
Update all mods on the spreadsheet to make sure I have all the 1.3 compatibilities down. DONE!
Add the mods that were released after I stopped adding them to the library. DONE!
Update the list to 1.5 as mods get updated. In progress, currently 395/1253 mods are updated to 1.5.x.
Move the Outdated section to the spreadsheet (not a priority).