HPCC is designed to run on thousands of nodes. At minimum, you need one current and supported Linux system to run a single node cluster. If you are interested in running HPCC on Windows please contact us. In addition, the ECL IDE is available for Windows and ECL Eclipse Plugin is available for all platforms. Detailed information is available in the system requirements guide.
Currently no single file can be greater than 4 exabytes (or 4 million terabytes). This is not a current concern as other limitations occur in real-world systems before this limitation is reached; such as total available disk space on your cluster. There are no theoretical limits to the number of files.
Logging in (e.g., being a registered user) allows you to post to the forums, contribute code and submit issues. Otherwise, anonymous users can only read these areas and cannot post or contribute.
No, you are free to keep your ECL source code for yourself. Only changes or improvements to the HPCC platform must be disclosed. There are no obligations attached to ECL programs.