UPDATE: Works with go 1.7 format, but tested only when DWARF info was provided; without DWARF info the heapdump cannot show much.
Heap dump reader & visualizer for Go 1.4
You call debug.WriteHeapDump(fd uintptr) to write a heap dump to the given file descriptor from within your Go program (that's runtime/debug).
The code in this directory is for a hview utility which reads a dump file (and optionally a binary that generated it), computes interesting data about the heap, and and presents the data to a web browser.
cd hview go build ./hview heapdump [binary]
then navigate a browser to localhost:8080 and poke around.