KTLV is acronym for Key-Type-Length-Value which mean a method which used to encode and decode your data.
KTLV was inspired by Apache Thrift. Thrift is more mature and more wide used, but it's Erlang encoder has a couple of disadvantages comparing with KTLV:
- it is 7 times slower in average;
- it produces a slightly bigger binary (near 8%);
- it's documentation is very, very poor and the source code is undocumented and contains no specifications.
On the other hand, KTLV provides only object encoding and decoding features and it is not kinda protocol or transport as Thrift is. Also there is no any Thrift IDL and IDL compiler in KTLV. You should implement your own codec for the programming language X by yourself instead.
The one of the most useful features KTLV taken from Thrift is keyed elements, which can help to achieve backward and forward compatibility between codecs.