Allan Gregersen is a researcher at Oracle Labs. He is currently primarily working on advanced HotSwap capabilities for Java on Truffle. His main research interests is Dynamic Software Updating and Developer Productivity tools.

Allan holds a PhD degree from the University of Southern Denmark. Prior to joining Oracle Labs, he was the inventor of Javeleon, a novel Java class reloading core based on bytecode instrumentation, which has now become the default reloading core in JRebel. Allan led the effort at ZeroTurnaround bringing the Javeleon technology into JRebel.