mod_sequester is a module for the Apache Web server 1.3 which allows you to control access to Web documents according to the date and time of the request. It provides four basic ways to control access: allow until time t, allow after time t, allow between times t and t', and allow except between times t and t'. It is useful for controlling access to time-sensitive things like press releases (disallow until after), special offers (allow until), or windowed 'this week only' opportunities (allow between).
mod_sesehe is an Apache module that disguises and removes the "Server: " HTTP header from responses. This allows you to hide certain information about the server. This also allows more accurate information to be provided if Apache is configured as a reverse proxy and a malformed request is received. Although sending the Server header in HTTP responses is not defined as a MUST in RFC 2616, the Apache HTTP Server does not otherwise allow you to disable sending this header via its configuration.
mod_sphinx is an Apache module which intercepts output bound for the client, whether it be from files served by the same Web server, files sent via reverse proxying, or files delivered by transparent forward proxying (outbound proxying, as in your browser's proxy setting). It opens the text and replaces a word with another word or phrase. When in regular proxy mode, it cannot modify SSL content since Apache cannot decrypt that (it would be a protocol violation).
mod_ssl provides provides strong cryptography for the Apache 1.3 webserver via the Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1). It is based on the SSL/TLS toolkit OpenSSL and supports all SSL/TLS related functionality, including RSA and DSA/DH cipher support, X.509 CRL checking, etc. Additionally it provides special Apache related facilities like DBM and shared memory based inter-process SSL session caching. per-URL SSL session renegotiations, DSO support, etc.
Mod_suexec_helper adds UserId and GroupId directives to Apache, which are passed as arguments to suexec when starting CGI scripts. This allows much finer control of which user and group ID scipts get run as, compared to suexec's normal SuexecUserGroup directive that can only be used once per virtual host definition.
Mod_trace_output is an Apache module that is designed to store the data that was sent to a browser, even if the request was for a dynamic page. It is possible to use it to generate statistics on the content viewed by users, and can store captured pages in files or in a MySQL database.