PowerShell competer for git
Import-Module TabExpansionPlusPlus # native completion of options works poorly without it
Import-Module ./PSGitCompletions.dll
Set-PSReadlineOption -ShowTooltip
cd <mygitrepo>
git com<tab> --am<tab>
git diff <ctrl+space> # Expands with list of 50 most recent commits
git diff added<ctrl+space> # Expands with list of commits where message contains 'added'
Extensive, multiline, tooltips are available in the ISE, but does not render well in the ConsoleHost.