What are the Server requirements to run Zen Cart?

[Mackinac Island]

PHP Version
Using the latest version of Zen Cart is always recommended for maximum compatibility.

Zen Cart v1.5.5 is designed for PHP 5.5 up to PHP 7.0 (and actually works with as far back as PHP 5.2.10* if really necessary for temporary upgrading purposes)
Zen Cart v1.5.4 is designed for PHP 5.5 and PHP 5.6 (and is compatible with PHP 5.3.7* and PHP 5.4 if posted bugfixes are researched and applied)
Zen Cart v1.5.3 is compatible with PHP 5.3.7* thru PHP 5.6 (or PHP 5.2.14 with weakened security)
Zen Cart v1.5.2 is compatible with PHP 5.3.7* thru PHP 5.6 (or PHP 5.2.14 with weakened security)
Zen Cart v1.5.1 is compatible with PHP 5.2.14 thru PHP 5.3.x.
Zen Cart v1.5.0 is compatible with PHP 5.2.14 thru PHP 5.3.x.
Zen Cart v1.3.9 series is compatible with PHP 5.2.10 thru PHP 5.3.x.
Zen Cart v1.3.7-v1.3.8a are compatible with PHP 4.3.2 thru PHP 5.2.x, but *not* PHP 5.3.
Zen Cart v1.2.x through v1.3.6 are compatible with PHP 4.3.2 - 4.4.x. They are NOT compatible with PHP 5.
The upcoming Zen Cart v1.6.0 is being designed for PHP 5.6 and PHP 7.x




PHP compatibility requirements of Plugins/Addons may vary. Consult each plugin's documentation and support discussion-thread for details.


PHP Memory Recommendations
- memory_limit suggested: 128M
- post_max_size and upload_max_filesize should be set to whatever max file size you or your customers may upload. Usually 8M is sufficient for most sites.

MySQL Version

Zen Cart v1.5.5 expects MySQL 5.1 to 5.7
Zen Cart v1.5.0-v1.5.4 expects MySQL 5.1 to 5.5
Zen Cart v1.3.9 is compatible with MySQL 4.1.3+ thru 5.1
Zen Cart v1.2.x thru 1.3.8a were designed for MySQL 4, and will give errors on MySQL5
The upcoming Zen Cart v1.6.x expects MySQL 5.1 to 5.7




Plugin/Addon-compatibility may vary.

Using the latest version of Zen Cart is always recommended for maximum compatibility.

Apache

Zen Cart works primarily with Apache 2.2, (or Apache 2.4 with the access_compat backward-compatibility mode enabled for v2.2 .htaccess rules support.)
The default distribution contains numerous .htaccess rules to aid in implementing security protections against malicious spoofing and other abuse. If you use a webserver engine other than Apache (such as perhaps nginx or IIS), you will need to manually recreate those same protections in whatever alternate security tools exist in your webserver software, or forego the benefits offered by them, and this would affect your PCI compliance.
Recommended Apache modules include: expires, headers, env, alias, deflate, ssl, mime, php5, rewrite in addition to other common modules.



Nginx and IIS?
Zen Cart is not regularly tested on IIS, but is known to work on most modern IIS servers. That said, we don't recommend IIS, and we don't provide any default-configuration scripts for IIS.

Some of the Zen Cart development servers do run Nginx, so we believe Zen Cart runs fine on Nginx. However, we do not supply an Nginx configuration file to optimize any caching or impose any directory-level security restrictions. (Whereas we do provide .htaccess files for Apache for those optimizations.) Thus, you will need to impose your own security and performance optimizations.


Perl and other languages?
Zen Cart does not use Perl.