IntelliCAD

IntelliCAD is a CAD-software programming toolkit and API published by the IntelliCAD Technology Consortium ("ITC"). IntelliCAD aims (at some levels) to emulate the basic interface and functions of . Unlike typical CAD programs, ITC IntelliCAD is not sold directly to end users. ITC IntelliCAD is exclusively licensed to Consortium members who pay fees in exchange for permission and guidance to include IntelliCAD technology in final OEM "IntelliCAD" (and other) products with their own end user license agreements. The ITC has nearly 50 members.

The IntelliCAD Technology Consortium ("ITC") is the non-profit organizational body of developers maintaining all vanilla-stock IntelliCAD source code toolkits and APIs for their CAD interface. The ITC also develops several advanced integrations with third-party technologies. These third-party technologies include the DWGdirect library (now called "Teigha for .dwg files") from the Open Design Alliance, which reads and writes the “.dwg” data format, and the ACIS 3D modeling kernel from Spatial Technology. The ITC office base is in Portland, Oregon, USA.

Modern IntelliCAD toolkits not only provide partial compatibility with .dwg, but also has a set of commands similar to by Autodesk, Inc. Similarly, IntelliCAD provides several calling convention routines, or APIs, such as LISP, COM, Visual Basic, and SDS (IntelliCAD's C/C++ Programming API) that allow users the ability to create complex custom CAD applications.

One focus of ITC development is improving compatibility between IntelliCAD and AutoCAD:

Toolkit features also include support for complex linetypes, multiline text, lightweight polyline, draworder, audit & recover, ADS support in most applications and raster image tools.

"IntelliCADD" began as an independent AM/FM/GIS (Automated Mapping/Facilities Management/Geographic Information System) software firm in La Mesa, CA USA. One of its products, AutoCAD Data Extension, allowed multiple users to access the same AutoCAD drawing, or have a single drawing point to entities stored in other drawings. Softdesk, the then-largest third-party product developer for Autodesk, acquired this company in 1994 and used the know-how to secretly develop an AutoCAD clone. Autodesk had recently entered into direct competition with Cyco Software (another third-party Autodesk partner), and Softdesk was concerned that the same could happen to them. The AutoCAD-clone project was kept semi-secret under the project name "Phoenix".