Squid (software) facts for kids
Squid project Logo
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| Developer(s) | Duane Wessels, Henrik Nordström, Amos Jeffries, Alex Rousskov, Francesco Chemolli, Robert Collins, Guido Serassio and volunteers |
|---|---|
| Initial release | July 1996 |
| Stable release |
6.11
 / 15 September 2024 |
| Written in | C++ |
| Operating system | BSD, Linux, Unix, Windows |
| Type | Proxy server |
| License | GPL 2.0 or later |
Squid is a special computer program. It works like a helpful middleman for your internet connection. Squid helps speed up how fast you see websites. It does this by saving copies of pages you visit often. This means your computer doesn't have to download the same things again and again.
Squid can also help groups of people share internet resources. It can even make your internet use a bit safer by filtering some traffic. While Squid is mostly used for websites (HTTP) and file transfers (FTP), it can also work with other internet rules like HTTPS. Squid is a free program. This means anyone can use and change it. It runs on many different types of computers.
Contents
How Squid Started
Squid began as a project called Harvest object cache. This was part of the Harvest project at the University of Colorado Boulder. Later, more work was done at the University of California, San Diego. This work was supported by money from the National Science Foundation.
A person named Duane Wessels took the last free version of Harvest. He changed its name to Squid. This was to avoid confusion with a paid version called Cached 2.0. The first version of Squid came out in July 1996. Over time, a version for Windows computers, called SquidNT, joined the main Squid project. Today, volunteers mostly work on Squid.
How Squid Works
When you set up a web browser to use Squid, it acts as a proxy. Imagine you ask Squid for a website. Squid goes and gets the website for you. But it also saves a copy of it. If you ask for the same website again, Squid gives you the saved copy. This makes the website load much faster! It also uses less internet data.
This is very helpful for internet companies. It helps them give faster internet to their customers. It's also great for computer networks in places like schools or offices. Everyone on the network can get faster internet.
Sometimes, Squid can be set up so you don't even know you're using it. This is called "transparent caching." All your internet requests go through Squid. This is common in offices. It can sometimes mean your internet activity is watched. If you are in the UK, organizations should tell you if your internet use is being monitored.
Squid can also help make your internet use more private. It can change or hide some information your computer sends. But whether this happens depends on who controls the computer running Squid.
Squid as a Reverse Proxy
Squid can also work in a different way called a "reverse proxy". Imagine you have a website that gets a lot of visitors. Sometimes, the main computer (web server) hosting the website can get very busy.
A reverse proxy like Squid can help. It sits in front of your main web server. When someone asks for your website, Squid gives them the page. If it has a copy, it gives it right away. If not, it gets it from your main server and saves a copy for next time. This means your main web server doesn't have to work as hard. It uses less power and less internet data. This makes your website faster for visitors.
One Squid server can even do both jobs at once! It can be a normal proxy for people inside a business. This helps employees get faster internet. At the same time, it can be a reverse proxy for the business's website. This makes the website load faster for customers outside the business.
Handling Partial Downloads
Websites often let you download only parts of a file. For example, if you watch a video online, you can click to the middle of the video. The website starts playing from there. It doesn't send you the whole video from the beginning. This is also how big updates for programs like Microsoft Windows work. They can download in parts. If your computer turns off, the download can pause and continue later.
Squid can help with these partial downloads. But for Squid to give you a partial download super fast from its saved copies, it needs to have the whole file saved already. If you start watching a video and then stop before it finishes, Squid usually throws away the part it downloaded. Special settings are needed if you want Squid to keep these partial downloads.
Where Squid Can Run
Squid can run on many different computer operating systems. These are the main programs that make your computer work. Here are some of them:
- AIX
- BSDI
- Digital Unix
- FreeBSD
- FreeBSD jail
- OpenWRT
- Raspbian
- Docker (software)
- Ubuntu
- pfSense
- OPNsense
- Kali Linux
- CentOS
- HP-UX
- IRIX
- Linux
- Red Hat Enterprise Linux
- SUSE Linux
- Arch Linux
- Linux Mint
- Debian
- webOS on Palm
- macOS
- NetBSD
- NeXTStep
- OpenBSD
- OS/2 (including ArcaOS and eComStation)
- SCO OpenServer
- Solaris
- UnixWare
- Microsoft Azure also Microsoft Nano Server
- Windows
Images for kids
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This robot is a friendly face for kids' information.
See also
In Spanish: Squid (programa) para niños
