Origin: https://github.com/harvesthq/chosen
NinjaMSP Chosen Fork
This fork includes
Custom 'add' option that allows the user to create an unavailable item directly from their search query. And an exact_match flag that will prevent the add option from appearing when a specific string is entered.
Fuzzy search sourced from: https://github.com/harvesthq/chosen/pull/2599/files [with minor bug fixes].