Screen is a full-screen window manager that multiplexes a physical terminal between several processes, typically interactive shells. Each virtual terminal provides the functions of the DEC VT100 terminal and, in addition, several control functions from the ANSI X3.64 (ISO 6429) and ISO 2022 standards (e.g., insert/delete line and support for multiple character sets).
The xterm program is the standard terminal emulator for the X Window System. It provides DEC VT102/VT220 and Tektronix 4014 compatible terminals for programs that can't use the window system directly. If the underlying operating system supports terminal resizing capabilities (for example, the SIGWINCH signal in systems derived from 4.3bsd), xterm will use the facilities to notify programs running in the window whenever it is resized.
x11vnc allows one to remotely view and interact with real X displays (i.e. a display corresponding to a physical monitor, keyboard, and mouse) with any VNC viewer. It is designed to be compatible with all Unix variants and Mac OS X, and depends on a small set of standard libraries. It supports SSL/TLS and VeNCrypt encryption, Unix password logins, single port access, Zeroconf, file transfer, and UltraVNC extensions. It is part of the LibVNCServer project.
rxvt-unicode is a clone of the well known terminal emulator rxvt, modified to store text in Unicode and to use locale-correct input and output. It also supports mixing multiple fonts at the same time, including Xft fonts, real transparency, and an optional embedded Perl interpreter that allows you to extend your terminal easily.
aterm (AfterStep term) is an xterm replacement, based on rxvt v.2.4.8. It includes features such as NeXT style scrollbar, resource efficient pseudo-transparency. It understands root background changes by AfterStep Pager and Esetroot. The primary goal of aterm is to provide cool visual features without resource consumption. It can be compiled to utilize AfterStep's libasimage for wider image format support.
Thinstation is a mini Linux distribution that enables you to convert standard PCs into full-featured, diskless thin clients supporting all major connectivity protocols like Windows terminal services (RDP), Citrix Ica, X, NX, telnet, ssh, etc. It can be booted from the network using Etherboot/PXE or from standard media like floppy/CD/hd/flash-disk etc. The configuration is centralized to simplify terminal management.
Twin is a text-mode window environment. It turns a text terminal into a X11-style display with window manager, terminal windows, and can also serve as display for remote applications. Each terminal window provides the functions of a text-mode Linux console. Twin runs on X11, libggi, itself, the Linux console, and any termcap/ncurses-compatible tty. It supports multiple simultaneous displays, and can attach/detach each display on the fly.