Nowadays, the teaching of programming concepts and algorithms is often conducted via slideware such as PowerPoint or Keynote, with the instructor going through a sequential series of slides showing static pieces of program code. As outlined in this paper, such a slidewarebased approach has its limitations in terms of the authoring as well as the delivery of content for a programming course. Nevertheless, there is a rich body of research on how to best teach programming concepts and algorithms where it has been shown that this process very much depends on the mental models developed by scholars when learning how to program. Based on this existing body of research, we derived a number of requirements for an improved source code visualisation and presentation in slideware tools. We present an interactive source code visualisation plug-in for the MindXpres presentation platform, which addresses these requirements and introduces a number of innovative concepts for an interactive visualisation of source code. Based on two concrete examples showing how our solution can be used for the teaching of recursion by means of a recursion tree or to explain sorting algorithms by using animation, we illustrate the extensibility and flexibility of the presented interactive source code visualisation approach. Ultimately, the presented solution should help in reinforcing a student's mental model about a presented algorithm and improve the knowledge transfer of presentations delivered in programming courses.