Those old enough to remember early computers and working on 5.25-in. floppy disks will also recall that they had to assemble a good amount of code to accomplish any kind of functionality approaching "computer-aided engineering." Thankfully, today, there is a wide range of "store-bought" software solutions available and only die-hard programmers need to write their own code for computer modelling. In the early days of microwave modelling and simulation, most programs were stand-alone tools, and results from one program had to be entered manually into a different program for analysis.

Modern software developers have realized that it is often necessary to create a PowerPoint presentation from a series of graphic files and MS Word documents, and integration of different software tools enables this functionality. The same is true for RF/microwave design, where it can be helpful to port files from one program, such as an electromagnetic (EM) simulator, into a circuit or system-level simulator. Making that integration as invisible or "seamless" (as programmers like to say) as possible is a key to the effectiveness of an integrated suite of software tools. And, as with Microsoft, it is sometimes wiser to use programs from a single software vendor rather than from different sources, to ensure that they are properly integrated and no "tricks" are necessary to make different simulators work together.