mod_deflate is available in lighttpd 1.4.42 and later. mod_deflate differs from mod_compress in that mod_deflate can compress any output from lighttpd static or dynamic. mod_deflate does not support caching compressed output like mod_compress.
max-compress-size is the largest response size that will be compressed.
min-compress-size is the smallest response size that will be compressed.
output-buffer-size is a per connection buffer for compressed output, it can
help decrease the response size (fewer chunks to encode). If it is set to
zero, a shared buffer will be used.
work-block-size is the number of kilobytes to compress at one time, it allows
the webserver to do other work (network I/O) in between compression.
max-loadavg is max system loadavg before bypassing compression (since 1.4.43)
mod_deflate currently does not stream compressed content in chunks. This affects very large dynamic responses, or dynamic responses sent in chunks with large time lapses between chunks.