The MapBasic development environment is a free download. To get your copy, follow the Location Intelligence Product Downloads link on the Precisely web site, at http://support.precisely.com. There is also information there about building custom applications and integrating MapInfo Pro into your application using the MapBasic development environment.
To obtain your free copy of MapBasic and access other resources to enhance your use of MapInfo Pro, you need to register on the Precisely site before accessing this download page.