This article describes how to program the
NXP LPC1788 based
IAR projects for the board provides full flash loader support (internal and external flash) and can be used, as is, to download applications through a J-Link debugger.
Keil is not supported.
For gcc, you can flash the uEZ board using SEGGER GDB Server described in this article. Simply replace the device type in the article with "LPC1788":
monitor flash device LPC1788
Note: Please see the article Overview: Compilers and IDEs for troubleshooting and general information.