What is mydumper? Why?

Parallelism (hence, speed) and performance (avoids expensive character set conversion routines, efficient code overall)
Easier to manage output (separate files for tables, dump metadata, etc, easy to view/parse data)
Consistency - maintains snapshot across all threads, provides accurate master and slave log positions, etc
Manageability - supports PCRE for specifying database and tables inclusions and exclusions

How to build it?

Run:

cmake .
make

One needs to install development versions of required libaries (MySQL, GLib, ZLib, PCRE): NOTE: you must use the correspondent mysql devel package.

Ubuntu or Debian: apt-get install libglib2.0-dev libmysqlclient15-dev zlib1g-dev libpcre3-dev libssl-dev
Fedora, RedHat and CentOS: yum install glib2-devel mysql-devel zlib-devel pcre-devel openssl-devel
openSUSE: zypper install glib2-devel libmysqlclient-devel pcre-devel zlib-devel
MacOSX: port install glib2 mysql5 pcre pkgconfig cmake (You may want to run 'port select mysql mysql5' afterwards)

One has to make sure, that pkg-config, mysql_config, pcre-config are all in $PATH

Binlog dump is disabled by default to compile with it you need to add -DWITH_BINLOG=ON to cmake options

This is all done following best MySQL practices and traditions:

As a precaution, slow running queries on the server either abort the dump, or get killed
Global write lock is acquired ("FLUSH TABLES WITH READ LOCK")
Various metadata is read ("SHOW SLAVE STATUS","SHOW MASTER STATUS")
Other threads connect and establish snapshots ("START TRANSACTION WITH CONSISTENT SNAPSHOT") ** On pre-4.1.8 it creates dummy InnoDB table, and reads from it.
Once all worker threads announce the snapshot establishment, master executes "UNLOCK TABLES" and starts queueing jobs.

This for now does not provide consistent snapshots for non-transactional engines - support for that is expected in 0.2 :)

Once can use --regex functionality, for example not to dump mysql and test databases:

 mydumper --regex '^(?!(mysql|test))'

Of course, regex functionality can be used to describe pretty much any list of tables.