I have a web application running on a Gentoo-based LAMP stack. My customers buy the software as a service and I host everything. However, there is some demand for on-site deployment inside the clients’ own networks.
Currently, because I host the system, there is no built-in license management in the app. I bill based on user accounts and data capacity (it’s a processing and analysis app for metering data) and I just set up whatever the client pays for and the client can’t setup those things himself. Even without on-site installation, that should be changed for better scalability anyway.
I am looking for a license managment framework and/or typical approaches that you have implemented yourselves or have seen to work well elsewhere. My requirements are:
- ‘safe enough’ rather than ‘military grade’
- very much non-obtrusive
- prevent the owner of a license from running the system in multiple plants when he has only licensed one
- make the number of user accounts and the data capacity both reasonably tamper-proof and easy to up- / downgrade
- work without an Internet connection (having a completely self-contained system would be the main point of opting for the on-site solution), though it might be acceptable if there has to be a temporary connection during installation
For some of the on-site scenarios, there would be a requirement for some particular OS, typically some version of Windows Server, but various Linux distros are getting more popular as well, especially in the public sector.
From a user’s point of view, I am quite satisfied with the license management in FogBugz, it seems Joel Spolsky is satisfied with it from a vendor’s point of view, and it is cross-platform, so it would make a great reference of what I’m aiming at.
Don’t. Every hour that you spend writing a license key system is an hour that you are not spending fixing bugs or adding features. By writing a license management system, you are spending resources in order to reduce the value of your product!
Copyright your code, have a lawyer and be ready to prosecute anyone who violates your copyright, and call it a day.