read of a message will require starting a separate program, a directory scan in a large directory and a file open before the data can even be accessed. On the other hand, mailbox formats such as mbox which use a single file often require insertion or removal of data in the middle of the file when messages are read or altered and this can be a very slow procedure. In these cases MH will be much faster. The maildir storage format made popular by qmail and the Courier Mail Server improves upon several features first shown in MH: a separate file per message, a separate directory per mail "folder," and exploitation of hardlinks and other advanced filesystem features for improved performance in space and time. Interface MH is inherently a command line based system. For a graphical interface, the original program was xmh, an X Window System application. After development of xmh ceased, a similar tool called exmh was developed in Tcl/Tk; and last updated January 7, 2004. Exmh is considered feature-complete and there has been little development beyond bug fixes. An Emacs interface to MH is also provided by the MH-E project. In addition to these dedicated MH clients, support for MH mailboxes is included in several other clients such as Claws Mail, Novell Evolution, Mutt and Sylpheed. See also List of email clients MH & xmh: Email for Users & Programmers nmh Message Handling System meillo's mail handler (mmh) References External links Current MH homepage Early history from MH & xmh: Email for Users & Programmers, by Jerry Peek Email storage formats Email client software for Linux Free email software Unix Internet software Software using the BSD license