-=zlib=
- Provides gzip/zlib/deflate encoding.
- Minimum version: 1.2.0.4
- Install on Debian: `apt-get install zlib1g-dev`
-
-
-#### Optional system libraries:
-
-The following system libraries are optional and provide additional features:
-
-=libidn=
- Provides IDNA support in URLs.
- Minimum version: none
- Install on Debian: `apt-get install libidn11-dev`
-
-=libidn2=
- Provides IDNA support in URLs (fallback if libidn is not available).
- Minimum version: none
- Install on Debian: `apt-get install libidn2-0-dev`
-
-=libicu=
- Provides IDNA support in URLs (fallback if libidn is not available).
- Minimum version: none
- Install on Debian: `apt-get install libicu-dev`
-
-=libcurl=
- Provides HTTP request functionality.
- Minimum version: 7.18.2
- Install on Debian: `apt-get install libcurl4-openssl-dev`
- Note: There are usually different styles of SSL support for libcurl available, so you can replace 'openssl' in the above command f.e. with 'nss' or 'gnutls'.
-
-=libevent=
- Eventloop support for the HTTP client.
- Minimum version: none
- Install on Debian: `apt-get install libevent-dev`
-
-### PHP extensions: