Ada.vim is a project mainly written in Vim Script, it's free.
Ada language default plugin
This is a mirror of http://www.vim.org/scripts/script.php?script_id=136
Perform Ada specific completion & tagging.
Provides mapping overrides for tag jumping that figure out the current Ada object and tag jump to that, not the 'simple' vim word.
Similarly allows
Exports 'AdaWord()' function to return full name of Ada entity under the cursor (or at given line/column), stripping whitespace/newlines as necessary.
See also Ada indent script, vimscript #137.