This is a Node.js library that generates a unique numeric ID. It uses the time in microseconds and a counter to cater for sub-millisecond accesses. These are joined to form a value that is passed back in json format.
It is similar in concept to Twitter's Snowflake project. Just a lot less code and more limitations. It cannot run on more than one server instance, but it can handle 4096 iterations within a single millisecond with rollover protection.
##Shortcomings No unique instance ID due to the limitation in Javascript's handling of large numbers. Even with this restriction, the timestamp will become too large and cause an overflow to occur. This will happen around the year 2079. If you adjust the starting epoch you could get around 69 years of reliable use.