This is a specialized scientific program for analysis of sedimentation velocity data from the Beckman Coulter XL-A or XL-I analytical ultracentrifuge using the DCDT method to compute the sedimentation coefficient distribution. It also will fit the g(s*) or dc/dt data to up to 5 independently sedimenting species using a unique algorithm to compute an accurate fitting function. It features a multi-document user interface and Explorer-style navigation through analysis steps and between analysis documents. It also allows overlays of the g(s*) distributions from different samples to provide quick visual answers to important questions such as "Does my protein reversibly associate?" or "Do these two proteins bind to each other?" DCDT+ runs under 98 or newer versions of Windows. Please see the author's DCDT+ WEB PAGE for description details.