What advantages do either method offer for html, css and javascript files served by a LAMP server. Are there better alternatives?
The server provides information to a map application using Json, so a high volume of small files.
See also Is there any performance hit involved in choosing gzip over deflate for http compression?
The main reason is that deflate is faster to encode than gzip and on a busy server that might make a difference. With static pages it's a different question, since they can easily be pre-compressed once.
if I remember correctly
I think there's no big difference between deflate and gzip, because gzip basically is just a header wrapped around deflate (see RFCs 1951 and 1952).
mod_deflate requires fewer resources on your server, although you may pay a small penalty in terms of the amount of compression.
If you are serving many small files, I'd recommend benchmarking and load testing your compressed and uncompressed solutions - you may find some cases where enabling compression will not result in savings.
Just for future reference:
Under a debian system (I'm on ubuntu) with Apache2 and the deflate module already installed (which it is by default), you can enable deflate compression in two easy steps:
a2enmod deflate
/etc/init.d/apache2 force-reload
And you're away! I found pages I served over my adsl connection loaded MUCH faster!
There shouldn't be any difference in gzip & deflate for decompression. Gzip is just deflate with a few dozen byte header wrapped around it including a checksum. The checksum is the reason for the slower compression. However when you're precompressing zillions of files you want those checksums as a sanity check in your filesystem. In addition you can utilize commandline tools to get stats on the file. For our site we are precompressing a ton of static data (the entire open directory, 13,000 games, autocomplete for millions of keywords, etc.) and we are ranked 95% faster than all websites by Alexa. Faxo Search. However, we do utilize a home grown proprietary web server. Apache/mod_deflate just didn't cut it. When those files are compressed into the filesystem not only do you take a hit for your file with the minimum filesystem block size but all the unnecessary overhead in managing the file in the filesystem that the webserver could care less about. Your concerns should be total disk footprint and access/decompression time and secondarily speed in being able to get this data precompressed. The footprint is important because even though disk space is cheap you want as much as possible to fit in the cache.