This pattern matches all the Unicode characters that are not allowed in an XML document. It's based on the Wikipedia article "Valid characters in XML".

accept empty spaces at start and end

Validate that the social security number follows all of the guidelines of the Social Security Administration, and excludes all voided numbers.

stackoverflow question

5 digits and no 0 5/4 times

Date Validation with leap year handling, & it takes care of date validation in the format like :mm/dd/yyyy or mmddyyyy or mm-dd-yyyy or m/d/yyyy or m-d-yyyy. 12/01/1986 02/29/2016 02/29/2015 13/31/1986...

This regex can be used to find all of the packages (.mum) files in the WINDIR%\servicing\Packages directory. I used it to remove the update packages from Winodws 7 pkgmgr /up:"filename" /norestart /quiet

Will return all matches of text between pipe placeholders, e.g. "This text has |two| placeholders |inside| of it" will return matches for two and inside.

Flexible regex to detect full or partial UK postcodes.

Everything, including proto, user:pass, host, query params and anchors

Will return domain portion of a url: Example: http://www.jkrowlings.com/books Returns: www.jkrowlings.com

Allows phone numbers with optional country code, optional special characters and whitespace

Check version of internet explorer - if is it usable for html5 support etc.

Includes resource strings, taken from here: https://gist.github.com/dperini/729294