Pioneer in Cloud computing, started with Amazon EC2 (compute) and Amazon S3 (storage) - IaaS. Now offers easy PaaS packaged services like Elastic Beanstalk. AWS has the longest catalog of Cloud services - Maximum flexbility for a developer
Started off as a PaaS provider (GAE - Google App Engine), but now full fledged with IaaS as well (GCE - Google Compute Engine)
An easy to use cloud provider (PaaS) which suits the needs of many web applications. Not exhaustive as AWS, but very popular as many applications can be realized here
The cloud platform from Microsoft.
A popular "batteries included" web programming paradigm.
Ruby with rails is very popular
Traditional web backend powerhouse, more popularly known as J2EE
Less is a CSS pre-processor, meaning that it extends the CSS language, adding features that allow variables, mixins, functions and many other techniques that allow you to make CSS that is more maintainable, themable and extendable.
Another popular CSS extension language, with a very good support in the form of Compass framework.
Probably no form of marketing is as impactful as reaching an interested user in his mailbox. Mailchimp provides very good service here.
These are the password-reset, purchase-confirmation kind of mails. Solutions like Mandrill helps to send such mails to your customers. An important requirement here is these mails has to be very realtime and not all email providers are capable of doing this.
You have a web domain and possibly a website hosted. How do you receive emails on this domain (say like email@example.com) ? Typically domain registrars provide few Inboxes free. I would suggest using Google Apps for Business. You get the gmail experience. They charge a nominal annual fees (Per Inbox, not email id)
Those errors/exceptions happening on your web backend. You need to know those are happenning to fix ! You also need info to fix it. NewRelic is a good service for this (though they provide lot more than this). You get alerted on errors and see nice graph on when what happend !
Servers have lot of logs - you definitely needs to have! - for issue debugging or forensic analysis when things go wrong. We are living in cloud and there are multiple servers in the cluster. Each web request goes to the one which is less loaded. Which server do you look into when something goes wrong ? You need some service which aggregates all the logs and shows them together - with good search capabilities. Services like Splunk and Loggly helps to do this.
The popular free analytics service from Google. Very easy to use.
Earlier known as Omniture Sitecatalyst. This is a paid product, but very feature rich. One great benefit is the possibility of getting raw data feed - important if you want to connect the analytics data to your service's backend - Beyond just reporting
Relatively new player - Paid product with pay as you go pricing. Since they focus ONLY on analytics, expect great detailing and agility