rxvt-unicode: fork of the well known terminal emulator rxvt
Its main features (many of them unique) over rxvt are:
Stores text in Unicode (either UCS-2 or UCS-4).
Uses locale-correct input, output and width: as long as your system supports the locale, rxvt-unicode will display correctly.
Daemon mode: one daemon can open multiple windows on multiple displays, which improves memory usage and startup time considerably.
Embedded perl, for endless customization and improvement opportunities, such as:
Tabbed terminal support.
Regex-driven customisable selection that can properly select shell arguments, urls etc.
Selection-transformation and option popup menus.
Automatically transforming the selection once made.
Incremental scrollback buffer search.
Automatic URL-underlining and launching.
Remote pastebin, digital clock, block graphics to ascii filter and whatever you like to implement for yourself.
Crash-free. At least I try, but rxvt-unicode certainly crashes much less often than rxvt and its many forks, and reproducible bugs get fixed immediately.
Completely flicker-free.
Re-wraps long lines instead of splitting or cutting them on resizes.
Full combining character support (unlike xterm :).
Multiple fonts supported at the same time: No need to choose between nice japanese and ugly latin, or no japanese and nice latin characters :).
Supports Xft and core fonts in any combination.
Can easily be embedded into other applications.
All documentation accessible through manpages.
Locale-independent XIM support.
Many small improvements, such as improved and corrected terminfo, improved secondary screen modes, italic and bold font support, tinting and shading.
Encapsulation of privileged operations in a separate process (improves security).