With IT budgets flat lining and CIOs feeling the pressure to reduce the spend on ‘keeping the lights on’ maintenance and support, it’s little surprise that more and more IT pros are looking towards the cloud to solve their problems.

With no initial upfront costs and with providers happy to manage the back-end of behalf of their customers, cloud is without doubt an attractive technology for many CIOs.

But there’s so many cloud providers, and a proliferation of services you can virtualise. This makes it a tricky proposition for CIOs looking to virtualise a whole range of IT services, and hoping to avoid getting ripped off when they do.

We’ve listed five cloud categories below, with two companies in each that we think are among the best at what they do.

Let’s start with…

Infrastructure-as-a-Service (IaaS)

IaaS cloud is probably the biggest one of them all. At its most basic, it’s companies offering virtual space for a price in which customers can host and develop services.

Amazon Web Services

AWS has cut prices ruthlessly in the face of competitors like Google and Microsoft. As a result, it’s a key player in the IaaS market, where it hosts the back-ends of the likes of music streaming service Spotify.

Now it’s also jumped into the virtual desktop space with Amazon Workspaces, through which you can rent a virtual desktop running in AWS.

Microsoft Azure

Redmond’s IaaS cloud is a close rival to AWS, and boasts predictive analytics, private storage and disaster recovery services in its extensive wrapping.

It has supported customers including Mazda and Lufthansa, and Marks & Spencers said a microsite it built in Azure took weeks instead of months.

 

Storage

Cloud storage can handle all kinds of structured and unstructured data – from documents to pictures, from multiple sources.

Google Drive

Google’s gone and upped its cloud storage offering by providing unlimited, free storage to all students.

The "infinitely large" service complements Google Drive’s regular 15GB free storage. It also combines the tools previously known as Google Docs, as well as all the files built with those tools, and offers the ability to create within Drive – an especially convenient feature when on the move.

Its compatibility with iOS, Android, Windows and OS X means it’s as useful on your desktop as on your smartphone.

Box

The enterprise-focused cloud storage firm Box offers 10GB of space for free. To differentiate its offering in the face of stiff competition, Box has introduced Workflow, an engine that automates the routing of documents and files as well as the actions people need to take on them.

That is an added bonus to its file-sharing service, which lets people work together on documents.

 

Desktop-as-a-Service (DaaS)

DaaS is a cloud service where the back-end of a virtual desktop is hosted by a cloud provider.

Citrix

The virtualisation specialist is a big player in the DaaS space, aiming to go beyond a simple hosted workspace. It also provides hosted applications, secure mobile device management and secure file sync and share services.

VMware

Whether it’s spun off from EMC or not, VMware is the virtualisation player. VMware Horizon provides remote desktop capabilities to allow users to run typically Microsoft operating systems like XP, Vista or Windows 7 within a virtual environment hosted on a server somewhere.

This is what’s known as thin client computing, where the desktop’s capabilities are virtualised, so the server in VMware’s data centre provides the processing power for your computer, meaning all you really need is a monitor, keyboard and mouse.

Meanwhile, VMware Workstation is a hypervisor (a piece of software that creates and runs virtual machines) lets people set up multiple virtual machines on top of their physical desktop.

That means you can run another operating system on your computer, or even run several. It can also simulate hard disk drives, and offers a web interface to connect users to local or server-hosted virtual machines via their desktop or mobile device.

 

Software-as-a-Service (SaaS)

SaaS is where software is hosted in the cloud, but appears on your device with full functionality.

Salesforce.com

Salesforce has turned into the go-to provider for SaaS CRM solutions, with Gartner stating the firm is dominating the market. With the arrival of Force.com, it’s pushed into the world of Platform-as-a-Service (PaaS) to try and get other firms to build apps it can offer as part of its service, expanding its offering greatly.

Insightly

One for the SMBs, Insightly provides CRM SaaS that integrate with Google’s Gmail and Google Apps, as well as Outlook 2013 and Office 365.

The idea is to help customers track their dealings with potential customers, with its SaaS apps accessible from both iOS and Android.

 

Platform-as-a-Service (PaaS)

PaaS is used by developers to build applications for web and mobile using tools provided by the PaaS provider – these range from programming languages to databases (eg SQL).

Red Hat OpenShift

This open source-based PaaS provider lets developers customise it as much as they want, and can be provided free as a trial (just 1GB storage is offered, though).

It comes in three variations: as a cloud-based service in ‘Online’, run from your data centre in ‘Enterprise’ and as an open source app hosting platform in ‘Origin’.

Heroku

This platform supports a tonne of programming languages, from Java to Ruby to Python. One of the earliest PaaS providers, it offers third-party apps as well as its own ‘dynos’ – virtualised containers that run processes in siloed environments.