I am calling their bluff that "Nxt is open source".
Rest assured, we have in the wings a better version.
Their? No one'd say such thing. More correct description will be: "Base code of Nxt (classes of objects, datathreads) went public 3rd of Jan, 2013, new features're testing as closed sourse, but anyone can decompile Java binaries and take a look, cos it isn't obfuscated".
Every open source project has their latest code released in a repository.
Bitcoin does. Litecoin does. Linux does.
Name one open source project that has 'new features testing as closed source'. Who knows if those 'new features' includes a keylogger.