The following plugins may be downloaded separately and installed, following information on the codex.

Bilingual Enabler
Makes several of Omeka’s core metadata fields bilingual. Instructions

COinS
Adds COinS metadata to item show pages, making them Zotero compatible. Instructions

Contribution
Allows collecting items from visitors. Instructions

Dropbox
Allows Omeka users to ‘batch upload’ a large quantity of files at one time, creating unique items in the archive for each file. Instructions

Geolocation
Adds location info and maps to Omeka. Instructions

Sitenotes
Administrative users can write notes about the site in an an editable space. Instructions

TagSuggest
When creating new items, the Tag Suggest plugin offers suggestions of tags based upon their frequency in the item textareas. Instructions

iPaper
Embed iPaper document viewers into your Omeka item pages. Instructions

PdfMeNot
Embed PdfMeNot document viewers into your Omeka item pages. Instructions