This is the appropriate license if you are creating proprietary applications and you are not prepared to distribute and share the source code of your application under the GPL license.
If you intend to derive a commercial advantage or profit from your application and to not release it under the GPL license, you must purchase a commercial license for Pergola.
Commercial licenses are on a per developer basis. Each and every person who directly or indirectly uses Pergola, or any of its components, to create an application or user interface, is considered a developer.
A commercial license is perennial and includes upgrades up to and excluding versions with the next initial number, for example: version 2.0 through 2.xx.
A commercial license is royalty-free.
A commercial license removes any obligations for the developer or publisher or entity to release the source code of the application/software/User Interface using Pergola, or any of its components, under the GPL license.