seamonkey doesn't seem to, or sleipnir.
Also I'm trying out seamonkey again because i can't make decisions
SeaMonkey IS basically an old version of Firefox + mail client (not Thunderbird) + IRC client.
Story of SeaMonkey:
Netscape appears and gets popular.
Microsoft introduces IE and war ensues.
Microsoft wins.
Netscape releases the source of Netscape as one last desperate attempt to gain users.
A new foundation named Mozilla is created, developing the old Netscape source openly, marketed as "Mozilla" or the "Mozilla Suite".
After a while Mozilla decides that the future lies in standalone applications, so they extract the browser component, which then becomes Firefox. Later on they also make a mail client based on Firefox (Thunderbird).
Some people decide to revive MZ as "SeaMonkey".
There you go.