do mods work at all with the new minecraft launcher?

Most people never use the profile system and if they do they almost never change the default game directory. The two significant things to focus on when using profiles are the version number (which we covered in the last section) and the Game Directory (which is where the game data is stored). The profile system in the Minecraft launcher is a very handy way to both make your Minecraft experience easier as well as keep your Minecraft words isolated from each other based on version number (and, if you've modded your client, based on mods too). On the opposite side of the gameplay spectrum, if you want to test out the bleeding edge features of the new experimental releases you'll want to set up a profile for the most current 'snapshot' builds so you can try out features that may take months (or longer) to reach the public release build. Mincraft 1.8 has been out for nearly three months as of this tutorial, for example, but the majority of multiplayer servers are still running 1.7.*. If you play online most multiplayer servers typically don't immediately update to the most current version as it is a huge headache for server owners to perform major updates.

If you want to preserve an older world you created without risking that world experiencing corruption or update problems when you move to a newer version of Minecraft, you'll need to lock the profile to the older version. Here are but a few examples of why you might need or want to manage your version number.

For other players, however, managing your version number (and creating separate profiles for different purposes) is an important component of the Minecraft experience.

Do mods work at all with the new minecraft launcher?