The kind of open-access materials most widely used on Wikimedia projects is figures from scholarly articles. This extends to historic publications, e.g. the benzeneformulae from Kekulé's original article that depict the molecule's two resonance structures.[1] However, chemical formulae are nowadays preferentially rendered in editable vector graphics formats like SVG.
A page from the lab notebook underlying the experiments described in Lang & Botstein (2011).[2]
Different kinds of media are being posted within articles or their supplements.
Featured "In the news" on the Main page of the English (originally without image, later with) as well as - with image - Thai (WebCite) Wikipedia on January 12, 2012, less than 24 h after the taxonomic description had been published by Eric Rittmeter et al. in PLoS ONE. By that time, the respective entries in the Dutch, Finnish, Portuguese, Russian, French, Bulgarian, Hungarian, Thai, Spanish and German Wikipedias, at Wikispecies and Wikimedia Commons had all been started, too - with images imported from the paper. Since then, the Paedophryne amauensis articles in the respective languages have also been featured on the Main pages of the French, German, Chinese, Finnish and Norwegian Wikipedias.