All playgrounds^Σ=7

Is given string a language code (as per IANA)

Is given string a valid media descriptor (including media query)?

Resolves custom-marked, cross-referenced paths in parsed JSON

Comprehensive, HTML-entities-aware tool to typographically-correct the apostrophes and single/double quotes

Replace chunks of whitespace with a single spaces

Finds and fixes common and not so common broken named HTML entities, returns ranges array of fixes

Helps to prevent widow words in a text