At your service.
Peleron's Brilliant Rebirth. You lead a party in a way very similar to Eye of the Beholder. Only one good enough to beat DMU in party division IMHO. Its biggest flaw is lack of portability.
GUILD. Not very much development progress lately but you take four adventurers and control one while fairly good AI takes care of the remaining three. At any time you can switch to others. It is not long though.
Rogue Mercenaries has you complete several missions with a team of units. It is important to look after them. A 7DRL with very familiar monsters if you have played StarCraft. Must take a look.
Embrace of Darkness. You venture alone at first but soon you meet other members of your own race who follow you and fight with you. Drop good stuff you don't need for them to pick up and use. Or even give your best gear since you tend to look after yourself better than they do. Has a lot of equipment slots but is slightly buggy and unmaintained since three years.
SewerJacks. Another good title. Inspired by Blood Bowl and Troll Slayer novels it invites you to descend with your buddies to sewers where you want to kill the big baddie. You need to team up with other sewerjacks found there. It is graphical.
Obdur somewhat qualifies because it allows you to play any character in the town but only one at a time. I do not recommend it though.
Finally if you want to have a multiplayer party you can try
Multiplayer Angband. Fine gameplay in realtime. The website seems to be down right now unfortunately. Hopefully it is a brief problem.
There was some *band which attempted to be party based but it was a failed try and I cannot find it now. Maybe some other time.