The cool thing about .NET is.. if you write your original app in C# and have performance issues, you can always call out to native for the small parts that are causing you issues. You are never stuck. It won't save you from a bad programmer, but it will save you from non-optimal 3rd party implementations.

What I mean by huge is an average of 4 to 10 gb each file. These files are generated by a mainframe process. By regulatory requirements, I can not modify the contents of the files or split then in any way. The MFC's CEdit and CRichEdit do have a limitation. Neither Notepad or Wordpad are capable of displaying these files in an acceptable way. I will appreciate wery much any help you can give me on this problem.