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vertigo writes "I am reasonably proficient in C and C++ as well as the more common scripting languages, but i always felt the lack of a sweet spot between the hard and fast low-level programming languages and the loosely typed scripting languages. Lately, my interest in the Mono project has been growing. The C# language appears to offer just that sweet spot between power and productivity I've been looking for, and its class libraries like Gtk# seem to provide the programmer with a very clean and intuitive API." Read on for vertigo's review of Mono: A Developer's Handbook from O'Reilly. Mono: A Developer's Handbook author Edd Dumbill and Niel M. Bornstein pages 278 publisher O'Reilly Media, Inc. rating 8 reviewer vertigo ISBN 0596007922 summary An introduction to programming with Mono

When learning a new language such as C#, or working with a new development environment such as Mono, it usually takes some time before you get up to speed in developing programs. Wading through the reference documentation and reading other people's source code often provides much-needed information on how to do certain things. Both, however, are very time consuming and tedious.

Enter Mono: A Developer's Notebook. This book provides a series of task-driven chapters which are thin on theory, but rich on practical content and example code. The featured code snippets are, in contrast to ones in books that teach theory and concepts, not solely designed to illustrate a specific theoretical aspect of programming. Each one is designed to perform a useful task that is essential in day-to-day application programming. What sets this book apart from the multitude of .NET books already available on the market? In order to answer this question it is neccesary to provide a short introduction on Mono.

Mono is essentially an open source cross-platform implementation of Microsoft's .NET development framework and implements the API's which are standardized by ECMA. It is, however, not an exact clone. Besides providing a (partially implemented) stack that provides compatibility with Microsoft's .NET API's, Mono adds a whole new API-stack of its own, consisting of open source technologies such as the Gtk+ toolkit and the Gecko HTML rendering engine. This makes it possible to develop cross-platform applications based on open source technology while (mostly) compiling from a single code-base. In contrast to most .NET books available on the market, which focus primarily on Microsoft's API's in the context of Visual Studio.NET, this book concentrates on the basic ECMA API's and Mono's own open source stack. A complete coverage of .NET and the Mono architecture is outside of this review's scope, so for more information you are advised to check the Mono Project's website.

Before we dive deeper into the content of the book, a short introduction on the Developer's Notebook series by O'Reilly may be useful. The books in this series are styled to resemble the kind of notebooks college students carry around during their classes in which to take notes or, more commonly, draw caricatures of their teachers. The 'notebook' theme persists throughout the look-and-feel of the book. The 278-page thick paperback has a glossy blue cover, complete with faux post-it note and coffee-stains. Inside, the pages are not clean white but lined like the pages found in math notebooks. In the margin, useful comments are scribbled in a font that resembles handwriting. At first I suspected that the 'busy' look would distract from the content, but in practice this was no problem, thanks to the thick black typewriter font in which the bulk of the text is printed.

The chapters in this book are referred to as labs. Each of them focuses on a specific set of tasks and/or features and is divided into several paragraphs. Most paragraphs consist of a number of standard sections following a rigid formula that help you understand a certain aspect of working with Mono. The most common sections are:

• How do I do that?: Often using a liberal amount of practical code, this section shows how to accomplish the task at hand, for example working with files.
• How it works: In this section, the code and concepts involved in the previous section are explained more in depth, step by step.
• What about...: Offers a short focus on more advanced topics or pitfalls.
• Where to learn more: If you are craving more information after reading the previous sections, you are often offered a helping hand on where to find more information, providing url's to relevant documentation such as MSDN and other websites.

The first chapter, Getting Mono Running, describes how to get Mono up and running on Linux, Windows or Mac OS X, and how to compile from source on other platforms. The installation instructions for Windows only describe how to install Mono and Gtk#. Integration of Gtk# only in an existing Visual Studio.Net installation falls outside of the scope of the book, but a recent blog entry offers some hints on how to accomplish this. Besides installation, the first chapter offers a short description of the individual tools that make up the mono development. After installation, you will want some kind of editor or IDE to work with. Both the MonoDevelop IDE and several other ways of integrating Mono into your existing environment as a Java or Windows developer are covered. Finally, the community is an important aspect of every open source project. Ways of interacting with the community as well as a guide on how to submit bugs and links to some working Mono/C# applications are part of this chapter.

The C# introduction in the second chapter, Getting Started with C#, is tailored towards people who have at least some proficiency in using an object-oriented language such as C++ or Java. Some differences between C#, Java and C++ are discussed, as well as the differences between value- and reference types, the basics of error handling, working with assemblies and more. Concepts such as classes, methods, inheritance and namespaces are assumed to be known territory. If you have no previous programming experience, Mono: A Developer's Notebook is only useful in combination with a book that teaches programming with C# such as The C# Programming Language by Anders Hejlsberg.

An important part of any modern language is its class libraries. The third chapter, Core .NET, provides an introduction to the standard Framework Library Classes, which describes essential everyday tasks that are part of every program, such as working with files, strings, searching for text patterns and handling collections of data. Besides those basic functions, the chapter also dives deeper into the internals of a compiled assembly, the handling of processes and easy multitasking using threads. Finally, the last paragraph explains how to use a .NET version of the JUnit Java Unit testing framework, Nunit, to test your code.

Developing Gtk-applications with Mono and C# is remarkably easy. Chapter 4, Gtk#, describes the basics of writing Gtk# applications. First, it's neccesary to remark that Gtk# might be a bit of a misnomer. Besides the raw Gtk+ toolkit functionality, Gtk# also includes most of the Gnome libraries like gconf, the gnome canvas, libglade and more. Chapter 4 describes functionality available in the Gtk namespace, the basic Gtk+ toolkit. Gtk+ is a constraints-based toolkit, which means that widgets are not positioned using absolute pixel coordinates but rather on basis of their logical relation to each other. This can be a bit confusing for novices, but this chapter provides a good introduction to the basic principles of writing layouts using Gtk#. The authors provide descriptions of essential operations that almost every application needs, such as creating menus and drawing pixmaps (or more advanced things like using the treeview widget and drag-and-drop), assisted by easy-to-read code snippets.

While chapter 4 introduces basic Gtk# functionality, chapter 5, Advanced Gtk#, delves deeper into more advanced features of the Gtk# library which also include functionality outside of the basic Gtk-namespace, such as the Gnome libraries. Working with Gnome button toolbars, the Glade user interface designer, storing your application settings in Gconf, setting up some preferences through the use of a wizard/druid, asynchronous operations and threading to increase responsiveness of your application while performing background tasks, rendering HTML in your application using the Gecko rendering engine and internationalisation and translation of applications are all described in this chapter.

The use of XML is tightly integrated throughout the Mono framework. It is, for example, the underlying format of the messages that web services use to communicate using the SOAP and XML-RPC protocols. The 6th chapter, Processing XML, describes the XML functionality available in Mono. It starts off by simple operations, reading and writing to an XML-file using relevant examples such as RSS and Dashboard clue-packets. It then proceeds to describe how to modify XML in memory, how to navigate and transform XML using Xpath and XSLT, how to constrain XML in several ways and how to serialize and deserialize objects into and from their XML representation. As in previous chapters, the information density is very high so it might take several reads to grok everything explained. The code examples and accompanying text however are very clear and concise.

The 7th chapter called Networking, Remoting, and Web Services describes the networking functionality available in Mono. The chapter starts off with ASP.NET. Mono's stand-alone XSP webserver and Apache integration with mod_mono are discussed, as well as the basics of writing a web application using ASP.NET's code-behind functionality which enables web applications to completely seperate presentation from the underlying code. Communication using plain tcp/ip, remoting using binary serialized objects and invoking remote procedures using XML-RPC as an alternative to SOAP are also described in this chapter. You might want to encrypt the data you send over the network, so a basic description of the Mono cryptographic API is provided. Finally, a short introduction to database handling using ADO.NET concludes chapter 7.

The 8th and last chapter titled Cutting Edge Mono starts off with an introduction on how to use the GNU Automake, Autoconf and the pkg-config tools to create an easy to build source package of your project. It then proceeds to describe various pitfalls and considerations in case you want to write cross-platform applications using Mono, such as filesystem layout, configuration storage and the calling of native code using p/invoke. A particularly cool project is IKVM, which translates Java bytecode into the Common Intermediate Language bytecode Mono uses. This enables Mono to run Java applications and allows Java and Mono code to inter-operate. A short introduction on the use of IKVM is provided, as well as some code examples on how to call Mono assemblies from Java and use the Java class libraries from within Mono applications. The chapter ends with some other cutting-edge functionality, like how to run a development version of Mono, a preview of the Generics (templates in c++) implementation available as featured in C# 2.0 and how to write Mono programs in Basic.

What is missing? The book doesn't contain a reference section on any of the described API's. If you need detailed information on the C# language specification or an API reference you will need to consult external resources such as the documentation provided with Mono, MSDN, or a separate book covering the topic to make optimal use of the information contained in this book. Fortunately, the book kindly provides pointers on where to find those. The information-density is much higher than you would expect from a book this size. This means the information contained in it is terse. Many topics are treated in a only a couple of pages and the book doesn't take time to explain a lot of programming concepts. The information gets you 'on the road' quickly however, which is exactly what this book is supposed to do.

The strength of this book is that it fills the gap between the earlier-mentioned reference documentation and the need to go out and try to read sourcecode to find out how a particular thing is done. The writing style is clear, concise and neutral. Some topics are clarified by the use of screenshots, which is especially useful in the chapters dealing with Gtk# widgets. All in all, if you are a developer with previous experience in object-oriented programming, Mono: A Developer's Notebook will provide you with an excellent introduction into many of the aspects of working with Mono, its associated libraries and programs.

More information and a sample chapter can be found at the book's homepage.

You can purchase Mono: A Developer's Handbook from bn.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.

Reader amoon writes: "With the rise of XML-based RPC (e.g. SOAP, XML-RPC, APEX), the distributed computing world is starting to really unsettle from the CORBA-RMI-DCOM oligopoly of the 1980s and 1990s. Yet, XML-based RPC is not a panacea (though it is quite cool), especially for those of us involved in the legacy and client-server worlds. Now, what is fascinating: the publishing world is revving up the engines on not only the XML-based RPC stuff, but also the RMI and CORBA stuff -- while rarely applied to the tech industry, the old adage, "what was old is new again," seems to fit well here. This review describes this über-cool trend from the RMI perspective, with a focus on Java RMI (O'Reilly) by William Grosso." Read on for the rest of the review. Java RMI author William Grosso pages 545 publisher O'Reilly rating 8 reviewer amoon ISBN 1-56592-452-5 summary Solid practical insight into the nitty-gritty details of RMI.

The Scoop

Remote Method Invocation (RMI) is the object-oriented remote procedure call (ORPC) facility for distributed programming in Java, since the 1.1 days. RMI also served as motivation and a proof-of-concept for jini, javaspaces, and numerous other solid distributed networking technologies. Of course, anyone from the academic distributed programming world knows Wollrath, Waldo, and Riggs.

Yet, despite a myriad of books over the past five years on network programming, RMI always seemed to be the stepchild: relegated to a single chapter (buried on page 496, of course) that always said that RMI was "better" than sockets and "worse" than CORBA. Now, granted that RMI is operationally rather trivial compared with CORBA and was (prior to RMI/IIOP) a unilanguage distributed ORPC technology -- but still. For those of us who have to interoperate with RMI (whether welcome from the Java world or not), the lack of in-depth technical analysis (beyond the spec) has been a hindrance.

Fortunately, this trend is finally starting to buckle with the release of several in-depth RMI books including: Java RMI, Java.rmi, and Mastering RMI: Developing Enterprise Applications in Java and EJB. As evidence of this problem, Grosso states the same in his introduction – and actually pulls it off without sounding self-serving.

I chose Grosso's text because of the cute squirrel (aka the O'Reilly brand), Grosso's recent series of articles on the hashbelt algorithm, and his unadulterated academic knowledge management and mathematics bent. Fortunately, I was rewarded: this animal returns to O'Reilly's pre-bubble quality. Koodoos to both Grosso and his editors (Knudsen, Loukides, and Eckstein) for getting the train back on the track.

What's to Like

Bottom line is that Grosso simply covers the topics and does so with solid conceptual and code coherence – even by O'Reilly standards (over 40 animals grace my shelves). His prose and explanatory patterns make it clear that he has actually gotten into the real-world of RMI, and doesn't hesitate to highlight both good and bad parts. You cannot be dozing off when you read this (at least not if you expect to understand it) -- this is written by someone with solid analytic thinking skills and it shows. After too many years of "there are no caveats" journalism and publishing, this is a nice reversion. Further, I can only imagine that his current employment is a testament to his real-world knowledge of RMI.

Grosso hits on a vein which is not well-appreciated: when not smoothed over by marketing people, RMI is actually a mostly-capable ORPC technology. Certainly activation and RMI/IIOP really began to make things interesting, from Java2 and EJB respectively. Discussion of reference-counted distributed garbage collection, a feature missing from CORBA and other popular ORPC standards, also contributes a nice bonus (although Grosso's ardent attempt to debunk the "RMI doesn't scale" argument is rather weak, even going so far as to rehash the definition of Threads and threadpools – this complexity mismatch is an ugly giveaway that a well-intentioned editor went astray).

What sets this text apart is the tight focus on nitty-gritty implementation details of RMI itself. After all, these RMI texts are way too late to the game to reteach how to write "baby RMI" code: 5 years after the original spec, you either know how to write RMI or you don't. Grosso simply gives you a solid in-depth analysis of all the obscurities of the RMI runtime, custom sockets, dynamic classloading, activation, MarshalledObjects, and HTTP tunneling. In other words, all the interesting real-world topics whose official documentation is poor and which the various RMI tutorials (written many years ago) ignored.

While canonical, the single banking example followed through the text was well-executed, although authors continue to underestimate the prevalence of readers who consume textbooks non-linearly.

What's Not to Like

RMI/IIOP is shaping up to be a fascinating contributor to the "cleanup the EJB mess" discussion. Dedicating a measly 13 pages (beginning on page 503, no less) to this critical topic seems a bit of an oversight – but maybe that is just my CORBA sentiments speaking. Either way, the mechanics of CORBA are sufficiently intricate in real-world deployments that saying "if you can build an RMI system, you can build a CORBA system" (p. 511) is a bit brazen (or naïve) for my tastebuds. I can only chalk up this oversight to deadline pressure, which is probably a Good Thing, since the book was supposedly in production over almost 2 years.

A minor point: the top-level organization of the book (Part I, II, III) is arbitrary, ignore it -- use the chapter organization instead.

The Summary

Quality: solid practical insight into the nitty-gritty operational implementation details of RMI in the real-world. You simply are not going to find solid O'Reilly-quality coverage of the topics elsewhere.

Relevance: If you are responsible for making RMI actually work in production systems, this might well be the next animal on your shelf – either now or later. If you want a breezy afternoon saunter around RMI, skip this. Instead, google one (of the many) free tutorials online."

You can purchase Java RMI from Fatbrain. Want to see your own review here? Just read the book review guidelines, then use Slashdot's handy submission form.

daveuserland writes: "Lots of activity in XML-over-HTTP. An article in today's NY Times about Microsoft, SOAP, UserLand and me. My comments. In the meantime XML-RPC keeps growing with solid interop. 29 implementations in the new XML-RPC directory. The politics are intense but everything's going well." It sounds like Dave understands this .Net thing; even after hearing about it for a few years, I've yet to hear a really lucid explanation of why I should want my apps and personal data floating in an amorphous cloud, but maybe that's just me.

daveuserland writes "Eric S. Raymond has discovered our XML-RPC project, going strong since early 1998. I don't think XML-RPC has ever been discussed on Slashdot. It's one of the most ambitious and successful open source projects, but not from the usual suspects. Raymond says: "XML-RPC is very much in the Unix spirit. It's deliberately minimalist but nevertheless quite powerful, offering a way for the vast majority of RPC applications that can get by on passing around boolean/integer/float/string datatypes to do their thing in a way that is lightweight and easy to to understand and monitor. This simple type ontology acts as a valuable check on interface complexity.""

daveuserland writes "Eric S. Raymond has discovered our XML-RPC project, going strong since early 1998. I don't think XML-RPC has ever been discussed on Slashdot. It's one of the most ambitious and successful open source projects, but not from the usual suspects. Raymond says: "XML-RPC is very much in the Unix spirit. It's deliberately minimalist but nevertheless quite powerful, offering a way for the vast majority of RPC applications that can get by on passing around boolean/integer/float/string datatypes to do their thing in a way that is lightweight and easy to to understand and monitor. This simple type ontology acts as a valuable check on interface complexity.""