No such agreement is required if the software is free

[ddevault]

This is not balanced at all: the employees do not have any ownership over the product of their labor. A better approach is to make your software (i.e. GitHub) free software and do not assign IP ownership at all, leaving the product collectively owned by all past, present, and future employees.

[erkinalp]

That is sadly not possible in some jurisdictions.

[BenjamenMeyer]

@ddevault it depends on the employment contract and jurisdiction. In the US, employers typically own work product; however, contractors can often maintain ownership - especially 1099 contractors - of their work product even as they grant licenses to the companies that contracted them (their employers in some respects).

Many open source projects also try to simplify the legal sides of things using Copyright Assignments (CLAs) - Qt, FSF/GNU, OpenOffice (historically, though that may have changed with Apache taking over) are some of the big ones. This lets the organization migrate licenses easier.

Further, as more and more employees engage with the open source world outside of work there is a new balance that needs to be struck. If someone signs onto an employer and their employment agreement assigns all IP of the employee to the employer whether its work product or not then that creates a large hurdle for the employee to work on open source since they technically have no legal ability to grant licenses of the IP they create during the active term of that employment agreement. And yes, I very recently saw an employer try to have those terms; leaving it to their discretion of when to enforce it - something no open source community would want to have as a risk.

So in the end, it's a really complex issue.