Meta: List of Wikipedias (English) - current statistics of all Wikipedias (including incubator wikis).
Wikistats - i.a. Chronological development of the number of articles in all Wikipedia
in the German language Wikipedia
Special: List of Wikimedia wikis - List of all WikiMedia projects and the associated links
Special: Interwiki table - Interwiki abbreviations for language versions, WMF projects and other websites
Wikipedia: Embassy - the “messages” (representations) of other languages in the German-language Wikipedia
Wikipedia: Edge of the field - international cooperation in solving problems
Wikipedia: Foreign Languages - Working with many languages and writing systems
Wikipedia: Encyclopedia - Encyclopedia on and relating to Wikipedia
Meta-project for coordination worldwide (English; partly translated)
meta: Wikimedia projects - List of all WikiMedia projects and the associated links
meta: Language version suggestion guidelines - How to start a new Wikipedia.
Wikipedia statistics - List of the number of native speakers of the respective language (the page can be updated with a delay of more than 2 months).
erwin85 / projects - Cloud / Helferlein, shows all over 900 WikiMedia projects and additional functionaries
Wikia: Incubatorplus - Wikia extension of the Incubator for languages without their own ISO-639 code
Handbook of the multilingual Wikipedia - General information on the multilingualism of the free encyclopedia and its language versions