I know they want really good things that they can use in their daily work. So I would like to share some of my own resources. You can add yours if you want.
Eclipse: Eclipse is probably best known as a Java IDE, but it is more: it is an IDE framework, a toolbox, an open source project, a community, an ecosystem and a base.
The JetBrains IDEs (RubyMine / PHPStorm / PyCharm, etc.) are built on the same platform and have excellent debugging tools and a very intelligent code completion.
Sublime Text – my text editor to go these days. Very fast with a wide set of accessories available. In addition, it is totally cross-platform. (Thanks to dgeneschi)
Firebug – It's a very useful tool if you ask me. You can see the code of a website with this Firefox add-on.
Web developer: it is also used to view the website code, but unlike Firebug, you can disable the CSS style sheets and all that.
ColorZilla: you can really know what color you want with this tool.
Using CSS: see what CSS rules are actually used.
Dust-Me – Dust-Me Select is a development tool that scans HTML pages to find unused CSS selectors.
NoScript: Allow active content to run only from trusted sites, and protect against XSS and Clickjacking attacks.
Pingdom full page test: test the loading time of a web page
Pingdom DNS Check: test the DNS servers and the configuration of a domain name
Pingdom Ping and Traceroute: test network connectivity to a server
Marking Validation Service W3C
net2ftp – web-based FTP client
Web design and development tools and software:
Dreamweaver: ideal for coding, editing and designing a web page. It can also be integrated with Photoshop.
Web Studio 5.0
Notepad: it's FREE because you can find it on your desktop.
Microsoft Expression Web
Shopping cart Scripts
* Thanks to Sahil for this *
http://oSCommerce.com – It's free and very good, but it will not have the features like that site.
http://zencart.com – It is also open source and is created by the creators of oSCommerce, but has more features than him.
http://opencart.com – It's also good and easily customizable.
http://viart.com: paid and free both, but I think you should mark Paid as they would have some of the features.
http://xcart.com – I used this but I left it because it does not have the payment gateways of our countries, but this script is extremely good.
http://livecart.com – It has very good designs and can be easily customized from the Administration Panel.
http://magento.com – Multi store (a shopping center) doing function.