Originally referred to "pulling yourself up by your BootStrap-s".
http://www.tuxedo.org/~esr/jargon/html/entry/boot.html Historical note: this term derives from 'bootstrap loader', a short program that was read in from cards or paper tape, or toggled in from the front panel switches.
Now typically refers to starting an activity with relatively few resources (more specifically, avoiding OPM), and having a mechanism to build momentum. Similar to (but different from, or may use) Viral Marketing, Lean Startup, Micro ISV, Grunt-Fund.
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