Some people like to do this using a dedicated diagramming software, like Microsoft Visio.
A friend of mine, who is a native English speaker, says that this sentence doesn't sound weird to him at all. But isn't it true that the word software is inherently a mass noun, so no articles are possbile or is he right that software can be used as a count noun to mean something like program and application? I actually have never seen software used as a count noun like that. I always thought that this word was a mass noun and could not be anything else. What do you guys think?