Who would have thought that...(I)
…the BBC has their own javascript library, glow. Their reasoning behind having their own library is quite interesting. Apparently, it is much more geared towards also supporting browsers that are not being supported by the popular javascript frameworks anymore.
Hence, if supporting old browsers is a requirement for you, you may actually want to have a look at this, since the library is licensed under the Apache 2.0 license and therefore should be usable within your project.