Richard, you will always need a development environment for programming. Since PSoCs are a bit more complex than "just a micro" why don't you want to use the (free!!) Creator IDE?
When you are running Linux or a Mac OS there might be a chance to get Creator running using a virtual machine. Use the keyword search at top of this page to get informed. Or are there other reasons why you hesitate using Creator 4.1?
I already use the PSoC creator...just to get some insights into the build system...especially how initialization is done...
Well at least I can program a HEX file generated from PSoC on Linux with the cypress_linux_tools...
me@s900:~/cypress_linux_tools$ ihex2cyacd -i SCB_UartComm01-stellaris-psoc42xx.hex -o uart.cyacd -b 3816 -c CY8C42
me@s900:~/cypress_linux_tools$ cyhostboot -p -f uart.cyacd
Programing file uart.cyacd
Start programing on serial /dev/ttyACM0, baudrate 115200
Got silicon id 0x04c81193, rev 0x11
Progress: array_id 0, row_num 30
Progress: array_id 0, row_num 31
Progress: array_id 0, row_num 32