Apache 2, the successor to Apache 1.

Apache is the most used Web server software worldwide.

Some new features in Apache 2: - hybrid multiprocess, multithreaded
mode for improved scalability

- multiprotocol support

- stream filtering

- IPv6 support

- new module API

New modules include: - mod_auth_db

- mod_auth_digest

- mod_charset_lite

- mod_dav

- mod_file_cache

Mod_ssl is no longer a separate package, but is now included in the
Apache distribution.

See /usr/share/doc/packages/apache2/, http://httpd.apache.org/, and
http://httpd.apache.org/docs-2.4/upgrading.html.