Again, the " office " environment was not represented for a long time in this area , but recently available. This will also come with a single or multiple , but limited license and are now mostly be registered with the manufacturer.
3rd Free or "open source " software. This is designed for general distribution and has to use, with the exception that it can not be changed in any way , no special restrictions. Of course, such software has its limits , but can also be very appropriate for serving many purposes. Virtually all types of software are to be found in this category.
A notable application distributes the software viber free download to read their documents freely , but to produce fees for the software documents . This policy is probably the driving force behind his drive to a position as an industry standard , as it is always certain that he receiver can decipher what is sent without long discussions about compatibility and versions.
Sure, there can be no piracy of products, in the third category , except that the code or code reuse for other purposes, but that does not seem to fall into a major topic at the moment , so we'll focus our attention on the first two categories.