Your presentation should comprise two main elements: a formal, slide based, talk about the software you developed and a demonstration of said software. The talk will cover similar ground to your final report: the design, construction and features of your software (justify/motivate your choices). You should also provide evaluation of the project: discuss where the main challenges were and how you solved them. The demo should show off the functions of your software, running there and then. The panel may ask to see specific functionality. It is often easier to present and then demo at the end. You might want to interleave presentation and demo. This is possible but it is certainly harder to make the presentation slick!
There is much advice available on the web concerning good presentation of technical material. We stress the following points:
Every member of the group should talk. It is usual for each member to discuss their contribution to the project. The presentation should begin with an introduction (probably from the group leader) giving an overview before you dive into the technical stuff.
Public speaking can be stressful. Know what you are going to say and practise. If you want to use cue cards don't use them as a script, outline the main points and use your own words. Make sure that you are able to deliver the presentation within the time limit. If you are running over, you will be asked to stop. We will indicate when you have only 5 minutes left.
Once you have finished presenting, the panel (comprising the supervisors of the projects in your session) will ask questions. Some questions may be quite challenging - don't worry! Take your time and if you are unsure what the questioner means, ask for clarification.
Your peers may also ask questions though these will be taken only once the panel are satisfied.