The normal operation of flymake allows the user to see the error message for a particular line by “hovering” the mouse over the line. This is inconvenient for people who try to use the keyboard for all input and for those who use the nox / no-window Emacs. FlymakeCursor was designed to address that: it displays the flymake error in the minibuffer region, when the cursor is placed on a line containing a flymake error.
The original code apparently is available at paste.lisp.org: flymake-cursor.el
It has since been modified to show the flymake error message in the minibuffer only after a delay. This prevents a distracting UI experience - messages quickly flashing up in the minibuffer and then disappearing - when a user cursors through a document that contains multiple flymake errors.
A similar capability is now available in nXhtml in the file util/flymakemsg.el).
The built-in package help-at-pt provides similar functionality, and also doesn’t clobber the minibuffer text. Example configuration:
(custom-set-variables '(help-at-pt-timer-delay 0.9) '(help-at-pt-display-when-idle '(flymake-overlay)))