Zed was developed using Microsoft Windows 2000, and so should be expected to run under any of the various editions of Windows, especially those based on Windows NT (XP, 2K, NT) but also those descended from Windows 95 (Me, 98, 95).

The installation program for Zed uses the Windows Installer technology for installation/removal of the software, which comes as part of the operating system for Windows 2000 and XP, and which can also be installed on other editions of Windows. As is becoming common with other installation programs, the installation program for Zed checks to see what version of the Windows Installer is available, if any, and installs or updates the Windows Installer as needed before continuing its installation.

Since the component edition of Zed exists as an ActiveX control, it is designed to be used primarily with Microsoft Internet Explorer. While third-party packages exist for allowing ActiveX controls to be used with other web browsers, these packages have not been tested with Zed to determine the extent of their support.

Zed has been developed and tested using Internet Explorer version 5.5 SP1, but does not depend in any essential way on any new features in 5.5. As such, it should work with any version of IE that supports ActiveX controls.

As an ActiveX control, the component edition of Zed can also be used with any other application that acts as an ActiveX container, such as Microsoft Word or PowerPoint.

Both the component edition and the application edition of Zed rely on the ActiveX control edition of the Integre techexplorer Hypermedia Browser for the parsing and display of MathML expressions. Zed uses techexplorer to parse both presentation and content MathML, and uses both the techexplorer DOM interfaces and techexplorer extensions, to send presentation MathML to techexplorer for rendering.

Because of the particular interfaces used, both editions of Zed require that techexplorer version 3.5 be installed. If techexplorer is missing, or if an older version is installed, Zed will display an error dialog, upon trying to load a document, reminding the user to install techexplorer.

Since Zed relies on the programming interfaces of the ActiveX control edition of techexplorer, note also that Zed requires that the Professional Edition of techexplorer be installed.

techexplorer provides methods for accessing the NamedNodeMap of MathML attributes for each element. However, while the techexplorer methods return the NamedNodeMap successfully, it is missing a pointer to its owner document, and so when it is passed as an argument to other DOM methods, techexplorer raises an exception when it finds the owner document missing.

Zed works around this issue by using alternative methods for getting and setting attribute values on MathML elements.

While techexplorer successfully collapses internal whitespace in Text nodes, it fails to trim external whitespace at the beginning and end of the character data for the node.

Zed works around this issue by trimming the whitespace itself.

techexplorer provides additional methods for controlling the version of MathML being used, and whether or not to allow the use of deprecated features. However, some of the method calls provided by techexplorer cause the state of these switches to be reset to their initial values.

Zed works around this issue by explicitly resetting the MathML version and deprecation flags after parsing MathML data from a string.

Under some circumstances, the DOM support in techexplorer appears to be deallocating and reusing pointers to node values in ways that affect the persistence of these objects across the component boundary.

Zed works around this issue in its handling of the DOM nodes it receives from techexplorer by checking the validity of the node type of the result from each operation.

Older versions of techexplorer previously produced invalid values for the name attribute, which is now obsolete in MathML 2.0.

Since the name attribute is not used by Zed it is simply ignored.

Under some circumstances, techexplorer exhibits a bug in the computation of the default value of the mathvariant attribute for token elements.

Zed works around this issue by overriding the default value of the attribute with the explicit value that would otherwise be used.

The treatment of characters with descenders in math mode in techexplorer adds horizontal spacing as expected by the TeX/LaTeX conventions for such characters. This spacing is undesirable for MathML elements, but appears in some cases in displaying elements created through the programming interfaces.

Zed works around this issue internally by using character entity references to these descender characters to avoid the added spacing.

The default handling of large operators in techexplorer sometimes produces undesirable results.

Zed works around the handling of large operators in techexplorer by specifying explicit values for the displaystyle, movablelimits, and maxsize attributes for large operators when they are used to display content elements in MathML.

When techexplorer displays stretchable operators that stretch horizontally, it may draw them with the wrong background color.

Zed works around this issue by avoiding the use of such characters in a stretchable context, by putting these characters in <mi> elements rather than <mo> elements.