On June 16, lead developer Brion Vibber announced the activation of the image undeletion feature on all Wikimedia web sites, following testing of the functionality added to the MediaWiki software over the preceding week. Image undeletion is the first aspect of the upload/image handling process to take advantage of a new codebase which allows for "file stores" to be defined, which will result in improvements to the treatment of uploaded files and media over the coming months.
Images can be undeleted in a manner not dissimilar to normal pages; administrators access the image page and select the "deleted edits" link, or visit Special:Undelete/Filename.ext. Selective undeletion is also available.
In an email sent to the wikitech-l mailing list, Vibber stated, "It's my hope that this will encourage admins to tackle the deletion backlogs a little more aggressively, since mistakes will be easier to undo." User reception to the feature was positive and many well-known users expressed their gratitude to Brion for this enhancement.
Image undeletion had been a long-awaited feature for MediaWiki, the bug report for which had been open since May 2005. Previously, images were discarded from the file system upon deletion. Under the new mechanism, they are passed to the file store, which moves them into an isolated location, while still allowing them to be retrieved and viewed, for previewing and restoration purposes.
Despite popular misconception, the absence of this function from the software was not due to policies restricting the storage of such content, nor due to disk space concerns; it was a simple lack of developer time to code the feature. This was made clear in the subsequent email exchange following the announcement.
Administrators of small wikis using the MediaWiki software who are not following Subversion trunk will find this option available to them as of the July 2006 quarterly release snapshot.