This is a list of Virtual Labs being used by institutions across the U.S. Licensing will vary. It can be found at the link below this paragraph, as well.
This resource is in use at Roger Williams University as part of a science course for non-science majors. This site includes units designed as part of the course, as well as information about how to implement a similar course. It is licensed to be freely accessed and distributed. Additional permissions may be available specific to each unit. The resource is also linked below this paragraph.