STM32F4 without ST Link module
While you can use the serial or (on the `407 USB or several other interfaces) bootloader, realistically, you should get a cheap SWD adapter.

You can even use a Discovery board for any SMT32 variant for this purpose, if you remove the jumpers that connect the stlink to the on-board target.

While the bootloader gets you only code loading, the SWD interface (with any of ST's Windows software, or on Linux/Mac either of Texane's open source tool, or OpenOCD) gets you code loading and the ability to have a breakpoint debugger.