From Persistent Security:
Professional license management software for your C/C++, Java and Python applications running on Windows XP, Windows Vista, Windows 7, Mac OS X, Solaris and Ubuntu. Full feature based licenses with version control. Lockable to several ID types such as the MAC address, IP address, Volume Serial Number, Hostname, Username, Country code, Mac OS X Serial number in addition to your own vendor hostid which can be anything you choose. In addition to a comprehensive floating license manager to manage all you concurrent license requrements. The floating license server runs on a single machine, a network or over the internet. Per-seat licensing makes it easy for you to sell your software affordably to a small customer as well as large customer and everyone in between. There are two Java applications included. The first is SafeGuardUser which is for the end-user to obtain the desired ID and to manage their licenses by being able to add, remove, test and display their current license configuration. The second application is SafeGuardManager which you use to generate your customer licenses and keep track of your customer database including company and contact information. The software developer kit includes all the functionality of both these applications so you can easily imbed this functionality into your own existing customer database and installation programs.
We have our own hardware key and SG allowed us to easily integrate our hardware key into their license management
Documentation expects you to already know license management
We have been testing their new Product Activation server where our software "phone's home" to get the appropriate license and completely eliminates any user interaction regarding license fulfillment. We control everything from demo licenses including what licenses are issued for which platform as well as all attributes of the license key through MySQL. We even use the product activation server in-house to allow our customer service reps to generate everything from demo licenses to paid licenses whether they are node-locked or floating. It is just too easy!!!