As the leader of MusicBrainz, I am also the executive director of the MetaBrainz Foundation, the non-profit legal parent of MusicBrainz. As the ED, I wear many hats -- here is my current job description:
Executive Director of the MetaBrainz Foundation
Server maintenance
Hardware purchasing/acquistion of used hardware
Colocation issues/contracts/maintenance
Managing hardware costs and future planning
Manage off-site servers (nl., test.)
Business Development
Conferences/tradeshows/schmoozing/maintaining contacts for MusicBrainz
Meetings with potential partners/licensees
New licenses sales
Managing and soliciting sponsors
Raise funds for further server development
Development
mb_server (and too little of it)
lucene searching
Legal Department
Licenses for data/software/web services
Contracts for data/licenses/web services
Interacting with lawyers
Find pro bono lawyers
Community Relations
Answering questions in IRC/mail/blog/mailing lists
Conflict resolution
Managing developers
Foundation Issues
metabrainz.org web site/donation tracking
State/federal filing requirements
Board of directors management/meetings
Accounting
Keep general books, manage invoices, pay bills
File tax reports/manage accountants
Post monthly financial results
Manage bank accounts/investments
Support
Answer support@ emails, with help from Wolfsong
Help partners/licensees (at least have support@ team help