The core code is written in C, but they're definitely using Lua in places, I believe they've incorporated some code from AlchemyDB... https://code.google.com/p/alchemydatabase/
From what I've read it could easily surpass Mongo, just look at the cost savings...
http://www.datanami.com/2013/09/06/aerospike_says_secret_to_...
"The second comparison (a video ad serving platform) had much bigger requirements, including a 5TB database processing 500,000 TPS. The hybrid SSD-DRAM setup running the AeroSpike database was able to handle the load with just 14 servers, at a total cost of $322,000, compared to 186 servers using NoSQL running on clusters of servers that use a lot of DRAM and cost $5.6 million."
From what I've read it could easily surpass Mongo, just look at the cost savings... http://www.datanami.com/2013/09/06/aerospike_says_secret_to_... "The second comparison (a video ad serving platform) had much bigger requirements, including a 5TB database processing 500,000 TPS. The hybrid SSD-DRAM setup running the AeroSpike database was able to handle the load with just 14 servers, at a total cost of $322,000, compared to 186 servers using NoSQL running on clusters of servers that use a lot of DRAM and cost $5.6 million."
They´re ACID compliant as well, which Mongo is not (AFAIK)... https://www.youtube.com/watch?v=nnxj77NNEeg