EZID (easy-eye-dee) makes it easy to create and manage unique, persistent identifiers. You can create identifiers for any kind of entity ? physical, digital, abstract, etc. For identifiers of objects on the web, you can use EZID to maintain their current locations so that people who click on the identifiers are correctly forwarded. You can also store citation metadata with identifiers to aid in interpreting and maintaining them. Several citation formats are possible. EZID supports a number of persistent identifier technologies, including ARKs (Archival Resource Keys) and DOIs (Digital Object Identifiers). Developed by California Digital Library. Written in Python, PHP.