Appendix F AutoLISP Basics and Advanced Customization Tools You may have heard of AutoLISP, VisualLISP, VBA, .NET Framework, Active X and ObjectARX. What exactly are they? These are all various programming languages, environments and tools used to, among other things, customize and automate AutoCAD beyond what can be done by simpler methods like shortcuts, macros and the CUI, all explored earlier in this book. To properly discuss all of these methods would take up quite a few volumes of text, and indeed much has been written concerning all of them. Our goal here will be to introduce the very basics of AutoLISP and only gloss over the rest so you at least have an idea of what they are. If advanced customization or software development work interests you, you can pursue it much further with other widely available publications. Overview I - AutoLISP This is really the very beginning of the discussion. AutoLISP is a built-in programming language that comes with AutoCAD, and is itself a dialect of a family of historic programming languages collectively referred to as LISP (List Processing Language). LISP was invented by an MIT student in 1958 and found wide acceptance in Artificial Intelligence among other research circles. The language and its developer, J. McCarthy have pioneered many expression and concepts now found in modern programming. AutoLISP is a somewhat scaled back version of LISP and is uniquely geared toward AutoCAD. It allows for interaction between the user and the software, and indeed one of the primary uses of AutoLISP is to automate routines or complex processes. Once the code is written it is saved and recalled as needed. The code is then executed as a script (no compiling needed) and performs its operation. One of the advantages of AutoLISP over other methods (discussed shortly) is that it requires no special training