X Window System: The Complete Reference to Xlib, X Protocol, ICCCM, Xlfd

This is a *reference manual*. You will want to read the Xlib Programming manual published by O'Reilly first. And you will only want this book if you want to program X11 directly, as opposed to using a toolkit such as GTK or Qt. Having said that, this is a *good* reference manual. It contains none of the usual boilerplate text all too common in badly written manuals. It explains every feature of Xlib and the X11(R5) protocols in detail, and how to make best use of them. It is concise, well-organized, and to the point. And the index is actually quite useful.The book is not entirely up-to-date. It would be better if it also covered some of the newer standards and extensions. There are some minor typos that might be corrected in the newer versions, but none that will give you any trouble. As the book focuses only on core protocols, you must look elsewhere for information on how to interoperate with Motif, Qt/KDE or GTK applications.In short, if you are going to write some program that uses Xlib or the X11 protocol directly, this book will help you. And the differences between X11R5 and X11R6 are relatively minor and of little interest to the kind of applications most people would write without a toolkit. But still, if you are a toolkit developer, I would consider buying a newer book.

This book has been updated and split into three books:X Window System: Core Libraries and Standards (1996, 700pp)X Window System: Core and Extension Protocols (1997, 700pp)X Window System: Extension Libraries (1997, 400pp)Each of the new books covers through X11 Release 6.1.I own this book, but I do not own the three newer books (I didn't know that they were replacements for this book). I contribute to the XFree86 project, an implementation of the X Window System, and I find this book to be useful in understanding the operations of X; I have not written a program that uses X11 directly, but I can see that this book (or its replacements) would be very useful when doing so.