At our company, all Engineering and Product Design team members use GitHub. We use its code repository, version control, and ticket tracking tools to store, maintain, and manage code for various projects. It works incredibly well at all 3 functions and is an extremely vital tool for our entire organization.
Pros
Version Control
Code Repository
Ticket Tracking
Cons
UI for non-technical users
Likelihood to Recommend
GitHub is a fantastic tool for software orgs that need to securely store their code, manage versions, and track bugs, enhancements, and the like. It's not especially suited for non-technical users.
We use GitHub to host our code, back it up with source control, and as part of our software development life cycle via code reviews using the pull request feature. We also use GitHub to review the code of open source libraries and contribute to open source in general.
Pros
Source control
Reviewing code
General ease of use
Cons
Searching through code
Outside collaborator functionality makes it hard to assign permissions correctly.
Likelihood to Recommend
GitHub is great for any organization who uses Git and needs to store its code somewhere accessible to all their developers. It's also great for an organization with open source projects. It's not appropriate for an organization who wants to retain complete control over their code.
GitHub is used by our technology departments for code review and versioning. At one time my team used Tortoise SVN, but code review was out of the question for that at the time. GitHub code reviews prevented many instances where a bug would have been introduced to a production environment. It makes the code review process easy!
Pros
Easy to use.
Great User Interface.
Notifications on comments/reviews.
Conflict resolution within GitHub now -- this is awesome.
Cons
GitHub Desktop apps are lacking. They can get out of sync and wonky.
A way to save queries/filters would be nice, so that I could go back to Closed pull requests to get objects (we extract objects from GitHub, manual migration).
Likelihood to Recommend
I don't think there are scenarios where it is less appropriate. Maybe if you are a one-person team! Otherwise, it is always well suited for large companies, small companies, you name it. The ability to go back through your history is priceless, and makes it very useful for any company, organization, etc. with code or files that need sub-versioning.