mercurialphrasebook

Similarities

distributed, so each clone has fully history
works on multiple platforms, ie. Windows, Linux, BSD
can create a new revision from any revision at any time (lightweight branches)
allows customisation globally or per workspace. monotone=monotonerc, Mercurial=hgrc
allows pushing/pulling/cloning with ssh

monotone does not give each revision a sequential integer ID, Mercurial does
monotone uses certs for core functionality such as branch membership, author, etc
monotone allows adding certs on revision for custom user information. eg. x-our-bug-id = #567
monotone certs are cryptographically signed
monotone certs + trust hooks can be used to ignore revisions
tags in monotone are certs, in Mercurial they are stored in a .hgtags file which must be merged if necessary
monotone history is stored in an SQLite database file and can be located anywhere. Mercurial history is stored in a .hg folder inside the workspace.
monotone does not use branch/author/date to calculate revision ID, Mercurial does. This means merging the same 2 revisions to produce the same result gives the same revision in monotone, Mercurial gives different revisions.
monotone tracks renames explicitly, Mercurial uses add+remove