Information for webmasters

As of September 2015, ISTEC member institutions are no longer required to have a dedicated server and a technical team capable of installing and maintaining the Celsius software, since this tool has been migrated to a centralized virtual environment. For more information, click here or visit the project’s web page.

We recommend the new institutions to contact the Celsius technical support team, at, to obtain their own instance of the software, completely free of charge. For more information about the benefits and tools provided by Celsius 3, we recommend you to download the Celsius 3 Administration Guide, available at the following link:

For institutions having already installed Celsius NT (2.0.9 and previous versions), please find information on how to maintain and update this software below.

Celsius requirements

Celsius is a software application built on PHP and MySQL, with low requirements. This implies that the hardware and software resources needed are very few.

Hardware requirements

Since Celsius is a relatively light software, it does not require a powerful server. Anyway, this will depend to a high degree on the number of concurrent accesses received by each Celsius installation and the volume of requests handled over time. In practice, a 1 Ghz server, with 2GB MB RAM and about 5GB should initially suffice.

Regarding disk space, user documents are stored in PDF format on the server. This means that the larger the number of requests, the greater the space required. Generally, 5 GB should be enough for the first years of work.

Software requirements

  • Operating System: Any operating system that supports a web server and php5. It has been run on Linux, Solaris and MS Windows environments without problems. The use of an updated Linux distribution or Windows server is recommended for greater stability.
  • Integrated web server with PHP. Apache2+, Nginx or IIS server. From NT versions of Celsius 2.x, PHP 5.2 or 5.3 is required. Some institutions have reported that it is also supported by PHP5.4, although this version is not yet officially supported. It is recommended to allocate at least 128 MB of memory for PHP.
  • MySQL database: It must be accessible on the same computer or on a remote computer. While it supports MySQL 4.1, MySQL 5 or higher is recommended

In addition, Celsius sends notifications by mail to its users. They can be sent directly from Celsius through the PHP e-mail function or you can configure Celsius to contact an SMTP server. For more information, please read Problems when sending e-mails.


%d bloggers like this: