`araxis`;;           Use Araxis Merge (requires a graphical session)
`bc`;;               Use Beyond Compare (requires a graphical session)
`bc3`;;              Use Beyond Compare (requires a graphical session)
`bc4`;;              Use Beyond Compare (requires a graphical session)
`codecompare`;;      Use Code Compare (requires a graphical session)
`deltawalker`;;      Use DeltaWalker (requires a graphical session)
`diffmerge`;;        Use DiffMerge (requires a graphical session)
`diffuse`;;          Use Diffuse (requires a graphical session)
`ecmerge`;;          Use ECMerge (requires a graphical session)
`emerge`;;           Use Emacs' Emerge
`examdiff`;;         Use ExamDiff Pro (requires a graphical session)
`guiffy`;;           Use Guiffy's Diff Tool (requires a graphical session)
`gvimdiff`;;         Use gVim (requires a graphical session)
`kdiff3`;;           Use KDiff3 (requires a graphical session)
`kompare`;;          Use Kompare (requires a graphical session)
`meld`;;             Use Meld (requires a graphical session)
`nvimdiff`;;         Use Neovim
`opendiff`;;         Use FileMerge (requires a graphical session)
`p4merge`;;          Use HelixCore P4Merge (requires a graphical session)
`smerge`;;           Use Sublime Merge (requires a graphical session)
`tkdiff`;;           Use TkDiff (requires a graphical session)
`vimdiff`;;          Use Vim
`winmerge`;;         Use WinMerge (requires a graphical session)
`xxdiff`;;           Use xxdiff (requires a graphical session)