Igor Pro is an extraordinarily powerful and extensible graphing, data analysis, image processing and programming tool for scientists and engineers.
The NIDAQ Tools MX package adds support for data acquisition directly into Igor Pro. It supports most "multifunction data acquisition" boards made by National Instruments.
The Igor XOP Toolkit allows a C programmer to extend Igor Pro. You can add operations, functions, menus, dialogs, and windows for data analysis, data acquisition or other purposes.
Igor Pro 8
Igor XOP Toolkit
Igor NIDAQ Tools MX