If you need an interactive solution for differentiation for files or folders, or an interface-less comparison computing solution, then the component version of ECMerge is perfect for you.
For the ActiveX version, download the SDK and use the examples provided for Internet Explorer, Visual Basic or .Net. Get a look to the on-line demonstration. ECMerge Active works in Internet Explorer from version 8 to 11 (in 32 and 64 bits)
To evaluate the command line version, download the full version of ECMerge. Install it, and search for the samples directory. You will find there examples and how to use the command line. The examples are written for Windows and Unix platforms separately, they cover the same usage cases.
This version exists under Windows as an ActiveX component, and as a standalone program guided by command line arguments and scripts which can produce results as text and XML.
ECMerge Component is sold in a "a la carte" formula: you pay for what you actually use, and depending on who will use the component (your clients, your own staff, on your website or redistributed inside your application)
During the phase of evaluation and maintenance, you will be in direct contact with the developers of ECMerge: a responsive support of quality.