It's a set of new alternative models by different authors, converted from initial Quake .mdl format to Half-Life .mdl format for using in "Quake Remake...
Quake Remake Upgrade it's a small project, which aim is to help you with using of different HD content (already created for original Quake game by its' fans) in Quake Remake. Because of differences between Xash3D (the engine of Quake Remake) and those engines, which are intended to use new HD resources (e. g. models and textures) with Quake, you cannot use such contents directly in Quake Remake. So you can find here already adapted and easy-to-use packs of models and textures for Quake Remake. All credits are going to ID Software and to respective authors of initial models and textures. You can find details about authors with every separate pack for download.
Here is a short guide about those packs which are already done.
Fixed LD models - highly recommended pack. It contains all models of Quake Remake (default low definition style) with different fixes and improvements. Should be installed before all other packs (if they are including any alternative models). You can install this pack even if you prefer LD style of the game, there are no any new models or textures, just better versions of initial ones.
Better FX pack - recommended pack. It contains better (HD) blood decals, gibs', fire and lightning textures, new explosion effect, plus two better textures for gold and silver key (as a little bonus :) ).
QRP HD-textures - highly recommended pack. It contains high quality HD textures for maps, map items (ammo, medkits etc.) and weapons (for default models).
Fragger's monsters textures - HD textures for monsters. Old looking style, but better (higher textures' resolution, better colors, more details etc.).
Quake Reforged Bestiary textures - very serious retexturing pack for all monsters. Most of textures are up to 2048x1024 px and higher, very detailed and brutal :) .
Deathmatch Pack by PrimeviL - set of HD textures for default LD models (there are mostly weapons and items). Recommended, if you prefer do not use Plague's Pak or HD models by Ruohis.
Plague's Pak HD models - pack with new, more detailed models for weapons (all, except axe) and some items. I made third person versions of weapons for this pack also (with prefix p_* in their names).
HD models by Ruohis - pack with new, more detailed models for all weapons and for the most of items (armors, keys, gibs, runes, power-ups, projectiles).
Miscellaneous models - just a set of random models (items, gibs, projectiles) by different authors, which can be used as alternatives for Plague's Pak or for HD models by Ruohis.
Feel free to combine these packs in any way you like. All information about installing etc. is attached with every pack. Most packs contain alternative versions for some of textures or models.