OpenWebRX has recently been updated and now includes a 3D waterfall display and a BPSK31 demodulator. OpenWebRX is a popular program which allows you to stream an SDR like the RTL-SDR over the internet efficiently. A number of clients can connect to your server and tune anywhere within a predefined bandwidth. Many examples of OpenWebRX running on RTL-SDRs and KiwiSDRs can be found on sdr.hu.
The 3D waterfall is quite an interesting feature as it allows you to visual signal strength, frequency and time all at once. BPSK31 is a popular amateur radio digital mode for making QSO’s (contacts). The new decoder allows you to zoom in closely on the band with high resolution and select with the mouse which BPSK31 channel you’d like to decode.
András Retzler, creator of OpenWebRX also writes that he’s now completed his Masters Thesis (congratutions!) on the topic of “Integrating digital demodulators into OpenWebRX”. His thesis is available for download here and looks to be an interesting read.