Based on a script written by Splarkaon Wikipedia and rewritten to use jQuery by Grunny, this script works in both Wikia and Monobook skins. It provides a link to a batch undelete form that allows you to list pages to be undeleted, through the API. This script is, essentially, the opposite to AjaxBatchDelete and functions similarly. Nerfmaster8 and Noreplyz have updated the script to using the second version of AjaxBatchDelete.
Note: In this example, pay close attention to the placement of commas and other punctuation. For people who aren't familiar with programming (and even those who are!), a common mistake when writing code is to accidentally delete, forget, or misplace critical symbols like commas or quotation marks. This can cause a syntax error that breaks the code. Carefully follow the convention shown here when using importArticles.
The option to use the Batch Undelete script will appear under your "My Tools" list in oasis and in the toolbar for monobook.
In order to undelete a batch of pages, just add the page names (not page URLs) in the form, each on a new line, and proceed to undelete them with a set reason. The script will stop when it reaches an empty line, and it can be terminated early by blanking the list of pages remaining to be undeleted.