Since almost all the papers reprinted here have already been reviewed in Mathematical Reviews, I shall not go into detail about their content but rather describe them in broad terms. As already indicated, the subject of most of van Douwen's work is general topology, but there are also numerous publications in related areas. In particular, these volumes contain a good many results about Boolean algebras. (Granted, Boolean algebras can be regarded as topological entities via Stone duality, but the flavor of the theories is somewhat different.) There is also work on measure theory, topological groups, and other areas. Particular mention should be made of set theory, whose connections with general topology are so close that many papers here that purport to be only about topology deserve the attention of set theorists. The survey paper "The integers and topology" (item [62] in this collection) served for many years as the primary reference for the theory of cardinal characteristics of the continuum. (Now it serves as one of the two standard references for this theory, the other being the survey by J. E. Vaughan [in Open problems in topology, 195--218, North-Holland, Amsterdam, 1990; see MR 92c:54001].)

Although eight years have passed since van Douwen's untimely death, his work is still of importance to general topologists and set theorists. These volumes will be of considerable value to those of us who regularly need to refer to his work. They will also be of historical value, as a record of trends in general topology and related areas during van Douwen's career, for van Douwen was usually at the forefront of the field. And for someone like the reviewer, who enjoys clever constructions, there is a lot of pleasant reading here, for many of van Douwen's papers are based on constructions of exotic examples. (Indeed, parts of van Douwen's work give the impression that examples were, for him, the primary content of mathematics, with theorems serving to clarify, limit, and organize examples.)

In addition to van Douwen's works, these volumes contain several useful preliminary sections provided by the editor. There is a chronological list of all the reprinted publications, with the original bibliographical data. There is a classification of these publications by subject, into ten categories: (1) Cardinal functions, (2) Cech-Stone compactifications, (3) Topological groups, (4) Generalized metrizability, (5) Compact spaces, Boolean algebras, and $F$-spaces, (6) Simultaneous extension of continuous functions, (7) Box products, (8) Measures, (9) Ordered spaces, and (10) Miscellaneous. There is a brief presentation of some unpublished results of van Douwen which were omitted from the posthumous publication project because they had been discovered, rediscovered, or extended by others in work already published.

Finally, in a most welcome addition to these books, the editor has listed the 200 questions raised by van Douwen in his publications and has added information about the present status of those questions, with references to the relevant literature. The questions are organized under the ten subject headings listed above. Many of the posthumous papers are also enhanced by notes, added by the editor or referee, giving updated information about the topics discussed in the papers. The notes, the questions (many of which remain open), and many of the papers should continue to provide ideas and inspiration to general topologists and set theorists (and others) for quite some time.