The Research In Motion Blackberry is famous for its connectivity. iMobimac Modem runs on a Blackberry and the Mac to which it is connected, and lets Mac applications access the Internet using the Blackberry's connection.

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Knowledge Forum 4.6's minor version number change belies just how different from its predecessor it really is.

Under the hood KF 4.6 has moved from using ZDBase for its backing store, instead using a tuplebase. This makes it possible to split HTML page generation into separate processes, potentially running on multiple front end machines. It also restores support for a rich client application, now written in Java, using ZTSoup to efficiently communicate changes in the tuplebase, whether made by other clients or by the web interface.

Initially I provided Java access to a tuplebase instance by implementing Java classes whose most interesting methods were marked as native, and thus invoked via JNI. This was very powerful because Java could use any tuplebase implementation simply by calling the appropriate factory function and I could expose any existing C++ functionality simply by implementing the appropriate JNI glue.

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ZooLib's tuplebase is derived from the tuplespace concept initially explored in the Linda coordination language, another well known derivation of which is Sun's JavaSpaces system. Whereas JavaSpaces is Java-only and relies on many of that languages's features, ZooLib's tuplebase works today with C++ and Java, and is well suited to work with other languages.

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For most of my career I've been very suspicious of dynamic data representations. After all, what's the point of having a compiler if it isn't provided with enough information about the shape of the data being manipulated to tell you when your code is going wrong. However, that really only works for data created and consumed within a single application. In the mid-90s, every C++ framework worth its salt had a huge bunch of code dedicated to turning arbitrary C++ objects into something that could be serialized and regenerated as objects later; and in fact that's about as far as most people got with CORBA before giving up.

But most objects in a C++ program, if they're objects at all, simply don't need to be serialized. The ones that do have disparate needs, and special cases abound. The approach I've found most flexible and least intrustive is to provide ZTuple. In this context a tuple is isomorphic to a LISP a-list, Python or Cocoa dictionary, Perl or Ruby Hash or to a Java Map. It's simply a list of name/value pairs, where values can be primitives (strings, numbers, raw bytes etc), tuples or lists of values.

ZooLib provides a suite of facilities that read and write tuples to binary streams, generate and parse a well-defined and easy to read text format, and that can read and write appropriate data formats as tuples.

ZooLib is an Open Source (MIT License) C++ library that makes it easy to write one set of source and build an application for Windows, Mac and UNIX. It provides a foundation suite of facilities that in essence form a virtual operating system API, and wide range of higher-level facilities that build on that foundation.

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