If I want to sell a system as stand-alone in C # language, do I need some microsoft license? Any special records? Any specific contracts? Do I have any limitations?
If I want to sell a system as stand-alone in C # language, do I need some microsoft license? Any special records? Any specific contracts? Do I have any limitations?
Depends on the type of application and the components used to make the application.
.Net can be installed on any supported system for free, so I think it will only depend on the libraries you have used in your application. If you develop everything, you do not need any license. Who will need the license in the case is the user, who must read and accept the license of the .Net framework.
You can develop for Mono using C #, so the license has nothing to do with Microsoft, but with Mono.
On the plus side, you will need to accept the licenses of the components you are using. Check which ones they own, and take precautions, and get their licenses. If they are open components, just have knowledge of the type of license. Some require you to mention that you are using the library / component on your system's "on" screen, others require you to place a file next to the distribution (in the case of desktop applications).
Many open / free software imposes limitations and duties to distribute them. This is not to say that you can not sell, there is no relationship between selling and distributing. Most open source / free components and libraries can be sold as long as you respect the distribution boundaries.
Take a look at this site to learn more about open source licenses
If the software is not desktop, in the case of a web, web-service, or other application of the "in-cloud" type, then the licenses will also be related to the installation of dependencies and libraries on this server, as well as the installation itself Operating system being used on the server:
Operating System: You must accept the OS Terms of Use
Database: You must accept the SGDB terms of use
Other softwares and services that the system depends on
HOST service: you must accept the HOST terms of service itself
In this case, it is verified that not all components are being distributed. In these cases, you should check only for usage and monetization limitations, but not for distribution.