For reference and for use in the Team Galileo Discord server, this page lists prominent mods made by this team's members.
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Galileo

JNSQ

Forum | GitHub
The successor to GPP, this planet pack re-defines the stock planets, adds more (roughly the same number as OPM) and is the flagship of native 2.7x systems.

GPP

Forum | GitHub
A stock scale planet pack which breaks many conventions, adds many challenges, does away with the stock planets and presents a star system as large as stock + OPM + a red dwarf star for other (small) | planet packs to add themselves onto. Its art style is realistic and all celestial properties are Mathematically grounded.

Stock Visual Enhancements

Forum | GitHub
The de facto cloud pack for the stock planets. Never install this alongside any planet packs that drastically change, or remove the stock planets.

Stock Visual Terrain

Forum | GitHub
This is a "skin" pack for the stock planets. It retextures them, makes them semi-realistic in art style, effectively changing them like a Kerbin-replacer. Therefore, this mod requires Kopernicus and is incompatible with any Kerbin-replacer planet packs.

Rescale!

Forum | GitHub
This mod provides the configs for all the standard scale options known with Sigma Dimensions: 2.5x, 3.2x, 6.4x, 10x, 10.625x.

Better Looking Oceans

Forum | GitHub
This mod was created to provide ocean texture options to players when a very rough time occurred for the mod, scatterer. It requires Kopernicus and performs more optimally than the stock ocean package.

FlareReplacer

Forum | GitHub | Content Packs
This mod was created to provide sunflare options to players when a very rough time occurred for the mod, scatterer. It requires Kopernicus and uses the Unity sunflare shader.

Play Your Way

Forum | GitHub
A tiny mod that enables you to play career mode with more of what you personally like and less of what you don't, such as turning off contracts completely.

Ship Effects Continued

Forum | GitHub
This mod produces IVA sound effects for increased immersion factor. The best known of these is hull stress under high dynamic pressure in atmosphere.

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JadeOfMaar

OPT Legacy

Forum | GitHub
Parts that were retired from OPT Spaceplane Parts (Main) by the original dev, K.Yeon, and parts added by JadeOfMaar and other modders go here. Proper releases/updates are done for this pack. Nearly all MM configs from this pack are consolidated alongside updated configs for OPT Main within OPT Reconfig, causing this pack to have a hard dependency on Reconfig.

OPT Reconfig

Forum | GitHub
This mod brings OPT Spaceplane Parts forward in gameplay features, gameplay balance and fixes. It is a utility mod, not a parts mod. It is required, however, by OPT Legacy.

Rational Resources

Forum | GitHub
This is mostly a gameplay and challenge mod, though, it adds a few parts related to ISRU. It makes resource placements specific to the expected class or composition of a KSP planet and heavily reduces the presence of stock Ore. It also easily makes planet packs more compatible with mods such as Cryogenic Engines, TAC life support and Kerbalism.

Airline Kuisine

Forum | GitHub
A small pack of Mk2 and Mk3 parts that adapt to the current life support mod and provides tankage and modules specific to that life support mod. Supported: Kerbalsim, TAC, USI, IFI, Snacks!

Thor Tech

Forum | GitHub
This mod adds a variety of electric engines (some old-chool, some sci-fi), parts for inline power generation and storage, and all-new options for thermal control. It's geared for survivability and smooth operation in atmospheres without oxygen and atmospheres with intense pressures.

SABR3 Sterling

Forum | GitHub
A very WIP mod which fully brings the Skylon SABRE engine and a form of the descendant concept SCIMITAR airliner engine to KSP. Its intercoolers exploit IntakeAir in a very similar way to the Skylon intercooler, and this mod is overall compatible with Nertea's Cryogenic Engines.

SunflaresOfMaar

Forum | Downloads: Stock system | SSRSS | GPP
A variety pack of scatterer sunflares. 5 families are available for yellow through red stars for planetary configurations linked above.

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OhioBob

GEP

Forum | GitHub
Grannus Expansion Pack is a small planet pack made specifically to populate the red star Grannus in GPP. It can also function as a Kerbin-replacer. No major contribution from Galileo himself is in this mod.

Eve Optimized Engines

Forum | GitHub
This mod clones some of the stock sea-level engines and tunes them for use on Eve.

Better SRBs

Forum | GitHub
This mod clones a few stock SRBs, noses and adapters and resizes some to 1.875m. It also adds thrust curves and gimbal to many SRBs.

Realistic Atmospheres

Forum | GitHub
This mod adjusts the stock planets' atmospheres to have appropriate stats for the stats of the planets themselves. For example, Eve's atmosphere gets much shorter and much thicker due to the gravity.

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Sigma88

Sigma Dimensions

GitHub
The best known of Sigma's mods, this enables easy and universal scaling of planets and stars in an install.

Sigma Replacements

GitHub | Table of Downloads
A suite of tiny mods that enable customizing of countless things in KSP. These are best demonstrated as a bundle in GPP. The member mods include: Descriptions, Heads, MenuButtons, MenuScenes, Navigation, Skybox, Suits, Textures.

Sigma Binary

GitHub
This famous mod makes it easy to arrange or produce proper binary orbits in KSP. It is well known through Plock-Karen of OPM.

Sigma Editor View

GitHub
This mod enables the actual outside scene (whether unchanged or as changed by any planet mods, sunflare mods and KK packs installed) to render around the VAB and SPH scenes. Time is still frozen while inside the editors, of course. It possesses a day/night toggle like the LightsOut mod.

Sigma LoadingScreens

GitHub
This mod enables the setting of your own screenshots and loading texts to display while KSP is starting up. It is prominent in GPP and JNSQ.