DigiPan stands for "Digital Panoramic Tuning” and brings the ease and simplicity of PANORAMIC reception and transmission to PSK31 and PSK63 operation. (digipan.net)
DigiPan is an easy to use PSK31/PSK63 computer software application. Initially released in 2000, DigiPan was one of the earliest (or perhaps the first) PSK31 software to feature the now-standard panoramic waterfall display for tuning. DigiPan sports all the features that are necessary for PSK31 operation and none of those that aren’t. DigiPan remains one of the most popular PSK apps despite not having been updated since 2004.
Platform: Windows 95 or greater
Price: Freeware
Download Here
Comments from subscribers – DigiPan’s strengths lie in its simplicity, as it embodies the QRP spirit. It does, however, lack customization features (for the waterfall colors, skins, etc.)
Thanks to Grant, VK4JAZ, for his much-appreciated feedback.
Platform: Windows 95 or greater
Price: Freeware
Download Here
Thanks to Dave, W8RIT, for his suggestion.
From Paul (in the comments):
Fldigi is FREE, and is a "Digital modem program for Linux, Free-BSD, OS X, Windows XP, NT, W2K, Vista and Win7". It does BPSK31, as well as a long list of other modes, and even works for the many of us who have move over to using a Mac! I would really suggest giving it a try:
http://www.w1hkj.com/Fldigi.html