All these mods are designed to connect to a vanilla server. The main goal is to improve performance for low end computers, but also give the options to make Minecraft look really beautiful if your computer can handle it. By default Distant Horizons is set to a very low render distance. Increase this if you would like things to look better. Add in fancy leaves or even shaders to take things to the next level.
Also includes a few quality of life additions like Mouse Tweaks, Better F3, and Xaeros Maps.