Last year the registration form for the WikiCON and WikidataCON was as as far as I know a GoogleForm. WikimediaGermany has a contract with Google LLC and it uses its product G suite. The meeting for the Strategy on tommorow is also in a Google product. At else for in the development department at Wikimedia Germany the product of a company called Roadmunk is used for the Projectmanagement of Wikibase. Surveys of the Wikimedia Foundation are also sometimes in Products of external companies. Especially Google is used a lot at the Wikimedia Foundation and at the Chapter in Germany. I dont know how it is used at other Chapters. Is there somewhere a list of tools from companies used by the chapters and the foundation and how many these tool costs. I think that there are also free solutions and there is the infrastracture to host such tools. So it were great if the foundation and the chapters keep more an eye on using free own hosted solutions instead of products of companies. One of the critism about Google is the big Market Power. This is a problem and I dont want to be a supporter of a company like this in too many topics of my spare time. For me it is enough to find information with the search engine. I dont need solutions of this company in other topics.
I think this page on Meta is a good start: https://meta.wikimedia.org/wiki/FLOSS-Exchange