"ArchivesSpace is open source software and free to download and use. It is not fee-based. We have a membership model to support the continuing development and sustainability of the application, and members receive benefits that help in their use of ArchivesSpace. Membership is optional and people can and do use ArchivesSpace without becoming members.
As you point out so well in your slides, while the software itself may be free, any open source software application has financial and opportunity costs, especially in terms of staff time and IT resources. This is all part of what institutions take into account in determining which application (if any) is best for their situation. Our hope in the ArchivesSpace community is that those considerations will be in our favor for many people, but we recognize that the archives community represents a vast array of needs and viewpoints and that there is no one size fits all solution to archives information management. We’re glad to be an option for people to consider, as well as a part of the archives community ourselves, and happy to answer questions or discuss needs with anyone who is interested." (from archivist listserve)