PsReadline replaces the command line editing experience in PowerShell.exe. It provides:

Syntax coloringSimple syntax error notificationA good multi-line experience (both editing and history)Customizable key bindingsCmd and emacs modes (neither are fully implemented yet, but both are usable)Many configuration optionsBash style completion (optional in Cmd mode, default in Emacs mode)Bash/zsh style interactive history search (CTRL-R)Emacs yank/kill ringPowerShell token based "word" movement and killUndo/redoAutomatic saving of history, including sharing history across live sessions"Menu" completion (somewhat like Intellisense, select completion with arrows) via Ctrl Space