A bit of good news for embedded Lua users, specifically on the topic of Lua on a MIPS chip :-)
A PIC32MZ EF Family data sheet recently popped up on Microchip's data sheet RSS feed . FPU on the chip finally! No official announcement yet, and it's not in the PIC32 parts table, so probably no customer samples etc yet. It's just a data sheet drop before PR releases, advance info, but I think we should be able to buy it this year.
So finally there will be a MIPS part that can run standard Lua with floating point hardware, and minimal source code changes, and can be easily purchased by normal folks . For those who don't want to peruse the data sheet, it's 200MHz, up to 512KB SRAM  and up to 2MB flash on chip. FPU throughput is mostly 1 cycle, latency for ADD/SUB is 4/5 cycles. Downside: the errata doc for its predecessor PIC32MZ EC family was very long...
 there is Ingenic, but it's kinda hard to source
 a goodly amount of RAM for Lua on an easily solderable TQFP (everything else with >=512KB SRAM on Farnell is a BGA part)
Kein-Hong Man (esq.)
Kuala Lumpur, Malaysia