IntroductionNext frontier for word processors and text editors of all kinds: an "idiom checker". One obvious purpose: in multi-nationality work teams, to point out to writers that they may be using idioms unfamiliar to other nationalities. Conversely, for the non-native speakers, to highlight idioms, and offer immediate, integrated translation.
Develop this as an open-source project.
Crowd-sourced library of idioms. Somewhat like Urban Dictionary, but more curated, along the lines of Wikipedia.
Ability to obtain a structured extract, for local usage and packaging.
UI ConventionsSomething comparable to the now-ubiquitous red-squiggly underline that signifies a misspelling. I am thinking maybe a purple, dashed underline.
For definition lookup, I am thinking a two-stage presentation, along the lines of Amazon Kindle. E.g., a mouseover brings up the first, short, most common definition. A right-click brings up the option to "see idiom wiki page".
Nice-to-Have EnhancementsSome degree of "fuzziness"...e.g., identify "out of a clear blue sky" as being a trivial variant of "out of the clear blue sky".
Providing examples that replace the idiom with non-idiomatic formulations.
Rating the idiom in various dimensions: uniqueness (something will be lost in translation), triteness, ambiguity, frequency, age-group popularity, source .
To take the rating to the next level, define contexts: business, personal, official correspondence, journalism, general public announcements.
Notes "Sports" may be the 800-pound gorilla of categories, for frequently used business idioms.
 Since I can't make a purple, dashed underline with my text editor, I am substituting lavendar highlighting for the examples herein.