Generally speaking, these are made as web interfaces that are hosted on a company-wide intranet. This makes it simple to design the interface and even more simple to set up on company computers.*


Honestly though, you should just use whatever tools you're comfortable with using. If you wanna go C#, use ASP.NET. Java, I'd say use the Spring Framework. Of course, since it'd be a web interface you're welcome to use pretty much any language you want. I would recommend you use a SQL database either way, just because of the nature of the application.

*Know this from experience