Hello all, I recently found myself needing to do some data manipulation; I needed to take some data from a database and generate a series of XML files from it. In the past I've done most of this sort of work in Java, but this time I decided I'd take the opportunity to explore the state of the art of Haskell DB and XML libraries. As to DB, I tried using HDBC first. I was actually a little surprised how straightforward it was. My database (PostgreSQL) is directly supported, and the compile/install went smoothly. My first test connection program that typechecked worked as expected (!) and I was soon executing queries doing useful work with the results. I'd just like to take a moment to congratulate John Goerzen for creating a product with a low barrier of entry for using databases in Haskell. As I didn't really do anything beyond simple queries, can't comment on more advanced features. For XML, I wavered between HaXml and HXT (the Haskell XML Tookbox). I initially decided to use HXT because it has support for xml namespaces, which I was going to need, and because it just seems to be the most complete and advanced package available. The HXT install suffers a little bit from transitive-closureitis, but, overall wasn't too bad. However, I had a really hard time using it! The API is _really_ intimidating, and I couldn't find any basic tutorial-style documentation. The API docs are a little hard to use because related definitions are spread out over a bunch of modules, and the links don't always work. Also, the theses are nice, but they read like theses ;-) That's not what I want when I have a job to complete. Long story made short; I couldn't figure out how to create and XML document and serialize it to disk. I was reasonably motivated and I'm a pretty experienced Haskell programmer, but I had to call it quits after about 3 hours of struggling with it. Most of my programs would mysteriously fail to produce output OR errors! It was really frustrating. I ended up using HaXml instead and shoehorning in the namespaces by using attributes named "xmlns:xyz" etc. on the document root element (which is OK, but not ideal). The HaXml API was also tough to work with but was less mystifying than HXT's, and I eventually got it to work. I was a little disappointed by the results, because the pretty printer does some fairly bizarre things to ensure that it doesn't introduce extra whitespace into the DOM. I also had to do some futzing to make HaXml correctly escape literal text. Finally, the using the HaXml API to generate XML results in verbose code that's hard to read. I was hoping that I'd get results comparable to using xmlenc (http://xmlenc.sourceforge.net/) in Java, but I was disappointed by fairly low signal-to-noise ratio (although in all fairness, its probably comparable to using the DOM or SAX Java APIs). Overall, HaXml works, but feels a bit awkward, at least for this use case. Now taking a slightly closer look at HXML, I see that it may be the best choice for what I was attempting to do (although it also doesn't support namespaces). The simplified representation looks particularly nice for building XML from scratch. I may try rewriting with HXML and see how that goes. So that's it. I don't have any deep conclusions, but I thought I'd share my experiences in the hopes that they will be helpful to somebody. Rob Dockins Speak softly and drive a Sherman tank. Laugh hard; it's a long way to the bank. -- TMBG