Rainlendar is a free, open source application for creating calendars. It's meant to be used by individuals and small businesses alike. It has some features that make it useful for those who need the basic information about events on their calendars. However, it also has quite a few other features which makes it more attractive to certain types of organizations. Because of this, it is often bundled with free software applications. The intent is that the organization may use these free applications for their own data processing needs, while the creators get a cut of the sales.
Free software for any application can often be used by non-developers, but not always. Some free applications simply do not allow people to modify or create new applications on their own. Other applications may provide a means to download and install software, but allow that software to be used only with specific computers. Rainlendar is the latter type of application. It allows its user to run it on their own computer, so that they can use it as a tool to send emails and calendar entries. However, it is also designed to make sure that it can be used on computers from other companies, as well. This is meant to prevent theft of data and to prevent infringement of copyright.
A free application like Rainlendar, however, should be examined closely. You should find out whether the software will provide the kinds of features that you want in your calendar application. There are many advantages to using such a software application, including ease of use, flexibility, and convenience. Many of these advantages, however, can be lost if the application does not function properly.