Generally, it can be said the new ILWIS is an improved version of its preprocessors while maintains major differences, conceptually and operationally, in number of areas. A brief summary of the most important differences between the new and previous versions are:
Format independency; this means no longer ILWIS objects and by extension ILWIS4 are tied to one data format. Format like GeoTiff, Shape, databases, remote data services and many more can be used as native data in ILWIS4 via data connectors. A data connector is kind of bridge that translates the external representation of data (e.g., Geo-Tiff file) into ilwis-objects internal data representation. This concept facilitates easy transformation of different data formats and provides reasonable flexibility for the users to read and write their data to various formats.
Platform independency; meaning the code base of ILWIS4 is now independent of the operating system and new ILWIS versions can be ran from platform using different operating system as well as Linux or Mac.
Use of external libraries; new ILWIS, besides having its own libraries, also integrates external sources of functionality. For example the excellent functionality of OpenCV and the Gnu scientific libraries can be used now in ILWIS4 via an operations connector. This provides extra flexibilities and additional analytical tools for the ILWIS users.
Python integration; the native scripting language of ILWIS4 is Python with an extension that enables the use of ILWIS functionality within python. Python extension can be used inside the ILWIS4 environment and/or as a standalone extension to python outside ILWIS4. Integration with Python, allows users to write high level scripts for multisource geoprocessing in a standard scripting environment, possibly running on different platforms. Even though, MapCalc and TabCalc and the whole scripting of ILWIS3, basically is not available anymore, but the new ILWIS, supports reading and executing the old style ILWIS3 scripts.
Upgraded data structures; the data structure as defined in previous versions of ILWIS was not sufficient and had shortcoming to handle hyper/multi-dimensional data (multispectral and temporal), commonly available nowadays. So, in the new ILWIS un upgrade was required not only for the data structures of the data sources but also for the supporting objects like domains and representations. As the results, ILWIS-objects provides a much better support for analysis of multidimensional data including hyperspectral data sets. Former separation between different layers/maps (points, segments, polygons) is replaced with Feature Coverage referring to all types of layers. Raster bands are stored in a single raster file and operations are applied to all the bands.
Workflows modeler; is a complex set of tools that tries to “model” the behavior of dynamic spatial systems in several conceptual layers including workflow builder, interactive input layer, dynamic modeling and conceptual layer. For example the modeler can creates Python scripts, workflows and higher level models such as Spatial multiple criteria evaluation. The modeler offers both a graphical front end as a pure text interface.
Multiple clients; the new ILWIS supports building multiple clients on top of the current ILWIS framework. In the past there was only ILWIS3 and creating another client was quite a challenge. Now, ILWIS4 is just a client and other clients can easily be written independently from user interface. The available clients are ILWIS User Interface (UI), command line, Python editor and DOS editor.
The new user interface; looks somehow similar to the previous version while in some area is quite different. For example, in ILWIS 4, there are no forms and display pop up dialog boxes, means everting is done through the Master Catalog. It has to be emphasized that the Master Catalog is much more than a simple view of folders on your disk. Any selected catalog is a view on the Master Catalog or, in fact, is a query made to the Master Catalog. A selected catalog can be any collection of data sources that “belong” together; which might be mandated by a simple physical reason, for example a folder on disk or a complex HDF5 file, or by logical reasons; e.g., the user wants to organize his data according to geographic and time filters. It also support data at different physical places but still forms one catalog. Moreover, there are also pictographic differences that can immediately be observed once you start the new ILWIS. For instance, the menu and button bars are removed from top of main window and is replaced with a “Tool Box Buttons” along right side of the main window and a data management panel at the bottom of the main window. Since, the new ILWIS does not support pop up dialog box for the data visualization, desired changes can be only applied interactively after the data displayed in a data panel. The data panel is part of the main window by default unless users wish otherwise.