If you are involved in projects which have a mix of HLL code along with Assembly i'd recommend Opengrok, i have recently shifted to Opengrok and find it amazing, Opengrok + Firefox + Extensions is the best combination in my opinion, a few firefox extensions like Scrapbook etc allow you to modify and add notes while you are browsing code, again this is mostly for 'Browsing' through code and not for modifying it on the fly.