Free Development Tools

Although Joel test number 9 states that you should use the best tools money can buy, that may not always be practical. If you want to get started in web development, or even set-up as a freelancer, you don't need to break the bank.

This is a list of some of the most useful and more importantly free tools I have come across over the years.

Web Based

Bitbucket
Free Git or Mercurial hosting for 5 users and unlimited private repositories. Always a good idea to have your code repo's backed up offsite, this is great for small teams or individuals
Uptime Robot
Get notified of site downtime, monitor up to 50 sites every 5 minutes for free. Don't wait for your client to tell you a site is down this service will email you.
NoIP
Free dynamic DNS, get up to 3 hostnames these expire every 30 days. Good for creating test sites that are externally accessible without having to buy domains or mess around with DNS.
MX Toolbox
Lots of diagnostic tools for troubleshooting DNS issues, but there is also a email blacklist checker you can use for free. This is good for monitoring your server does not get blacklisted.
Google mobile friendly test
Now essential more than ever check if your site is mobile friendly.
Google page speed insights
Check how your site ranks for page speed, Google will find the problems and suggest solutions.
w3 developer tools
Loads of diagnostic tools available to check for invalid markup,CSS,broken links,RSS feeds and mobile friendliness.
Fontello
Great for generating custom font icons from your own files or selecting from freely available font icons to create a custom set.
Fontsquirrel web font generator
Handy tool to generate font files from a TTF, this is useful if you want to host fonts on your server or you need to generate EOT,WOFF,SVG files.

Downloads

Visual Studio Community Edition
If you are developing with ASP.NET and C# then Visual Studio is essential. The Express edition has a huge amount of features for a free IDE.
Win Merge     
If you need to compare files this tool is excellent it can also be used as the default tool for viewing version differences with SVN or Git.
Notepad++
Really handy little text editor, great for converting or manipulating files. Lots of language highlighting options.
Jet Brains Dot Peek
C# Decompiler, need to have a nosy around a library then use this.
Jet Brains Team City
Another great freebie from Jet Brains, Team City is a continuous integration server that has a tonne of features and you can use it for free with 20 build configurations and 3 build agents.
Telerek Fiddler
Web Debug proxy, debug network traffic, simulate slow connections, test site security.
Keypass
Ensure you never forget those super secure passwords you generated by storing them in Keypass.