LyX document processor 1.6
21 August 2009
Reviewed by Felix Grant
This review began with the resolution of a need: to unify the efforts of several hundred volunteers into a single live, multilingual, frequently updated and heavily mathematical information flow from and within an ongoing study. LyX is a free, open-source document-processor system underpinned by LaTeX. No user knowledge of LaTeX is necessary (though it certainly does no harm). Once users have adjusted from word-processor habits, this greatly simplifies both content-editing and style conformity management, for both text and mathematics.
Compiled versions are currently available for Linux, MacOS and Windows, covering most users. Anyone used to the luxury cushioning of Windows may find the first installation confusing, since it requires that LaTeX and Postscript (or equivalent) substructures already be in place, but everything goes smoothly and there are automated download prompts for anything that’s missing.
Once in place, everything works intuitively and well. The program has a fully graphical user interface, with a ‘panes and bars’ structure very similar to that found in many other tools. Elements (including the table and mathematical editors) are WYSIWYG where it matters although LyX as a whole, in keeping with its philosophy, is not – precise output being monitored, if required, in DVI (device independent), PDF (packaged document) or other output windows.
Mathematics can be input and edited through on-screen ‘point and click’ bars, and this works well for users whose primary task is text entry with only occasional equation building. For heavier grade work, there is a good set of keyboard shortcuts, and more or less anything can be done without recourse to a mouse as these become internalised. There are math macros, (pre-built or user defined) and regularly used compound structures respond well to further aggregation through third-party keyboard enhancers. Because the underlying structure is LaTeX, anyone happy to get a short way into the works can copy and paste code directly from external repositories, and stock documents built or stored for the purpose within LyX.
AMS (American Mathematical Society) LaTeX libraries can be used (they must be explicitly enabled in the options menu), including choice of formula types. Theorem environment support is document-module based, so can be used with or without AMS.
LyX can also use external CAS (computer algebra system) engines, where they are available, to evaluate expressions within the document. I’ve not explored or tested this capability in any great depth, and there is a learning curve to surmount, but Maple, Mathematica, Maxima, and Octave were all picked up from the test system.
Essential academic writing tools such as foot and margin notes, citations (bibliographies being held in BibTeX databases), appendices, cross referencing, illustration enumeration, indexing, tables of contents, and so on, are provided and work well. Multilingual and bidirectional support are solid and impressive.
The main weakness is import of existing material, which can be problematic, the import filters not always working as expected and not including the gamut of file types which word processor users expect. This, to be fair, partly reflects the difference in philosophy between a document processor and other programs. The best strategy is to plan documents in LyX from the start, transferring external material either as pure text or by copy and paste.