Wikidata (In Progress) 
Due to the introduction of wikidata, interwiki bot will need serious modifications. Please refrain from running it on Wikipedia articles until it plays nicely with Wikidata. Please see Requests for comment/Wikidata rollout and interwiki bots for more information.
This section needs more information on how the new bot will operate
It is a challenge to maintain the links from an article in one language to all of the versions of that article in other languages. Each time a new version is introduced, changes name, or is deleted, all of the other versions should be updated.
We now have a mailing list at http://mail.wikipedia.org/mailman/listinfo/wikibots-l It is recommended that all operators subscribe to this list.
There is an interwiki bot coded in Python by Rob W.W. Hooft (c) 2003. It requests an article, parses interwikis and checks if the other wikis are up to date.
From the .py file:
- Script to check language links for general pages. This works by downloading the page, and using existing translations plus hints from the command line to download the equivalent pages from other languages. All of such pages are downloaded as well and checked for interwiki links recursively until there are no more links that are encountered. A rationalization process then selects the right interwiki links, and if this is unambiguous, the interwiki links in the original page will be automatically updated and the modified page uploaded.
The robot tries to be soft on the wikipedia server: it uses the new Special:Export feature to get more than one page in one request, and it waits between requests. The robot will (unless changed) not modify more than one page per minute.
This robot has a growing operator community.
Before being used on a wiki, its community should authorise such a bot to update the wiki. it can be tested on a small number of pages to demonstrate its purpose.
The best thing is to have an operator for each language that wants to run the robot.
Interwiki Bot FAQ 
Please see the up-to-date version at Yuri's talk page.
Some statistics: up-to-date reference
articles interwiki links average number en: 973k 1100k 1.1 de: 357k 856k 2.4 fr: 237k 720k 3.0 pl: 212k 637k 3.0 ja: 181k 476k 2.6 it: 140k 529k 3.8 sv: 134k 565k 4.2 nl: 127k 632k 4.6 pt: 112k 536k 4.8 es: 94k 556k 5.9 zh: 56k 407k 7.3 ru: 56k 357k 6.4 no: 49k 371k 7.6 fi: 47k 417k 8.9 da: 37k 359k 9.7 eo: 33k 327k 9.9 he: 32k 286k 8.9 hu: 25k 212k 8.5 ca: 25k 284k 11.4 uk: 23k 192k 8.3 id: 13k 170k 13.1 af: 4k 144k 31.3 la: 4k 86k 20.0
See Interwiki bot/Operators for a list of bot operators.
See Using the python wikipediabot for an attempt to get new operators started.
Operators of the bot, and in fact all people that want to discuss the implementation or the usage of this code, are welcome to join the mailing list firstname.lastname@example.org by subscribing at the mailinglist information page
Interwiki warnfiles 
- Interwiki bot/Warnfiles: recent warnfiles for bot operators can be found here.