Florin wrote an article about experimenting with MAX6955:
My experimenting actually started with MAX6954. After many failed tries due to SPI issues (Maxim uses a special interpretation of the protocol, I read), I switched to MAX6955.
MAX6955 is the I2C sibling of MAX6954 (which uses SPI). They both have identical LED driving abilities, only the microcontroller interface part of the chips differ. Once, both chips were available in DIP-40 package. Now, MAX6955 only comes in SSOP-36 (MAX6954 is still available in DIP-40). Luckily, the pin configurations for the two chips are compatible, which allows for easy swap. For this reason, I designed a breakout board (shared at oshpark), so I can use the same setup I built for MAX6954.
More details at Florin’s blog.