Jens and Martin talk about the different flavours of ABAP which are available. They focus on the different ABAP runtimes in the cloud, mainly on the new Steampunk environment embedded into S/4HANA cloud. Here are some additonal links: 

SAP API Business Hub 

Embedded Steampunk Blog Post by Boris Gebhardt 

Open SAP Course Introduction to ABAP in the cloud 

Open SAP Course Building Apps with the ABAP RESTful Application Programming Model 

ABAP Conf