It's not all about just renting office-based applications. Consider ASP services for websites. Perhaps you're using a hit counter on your website. Chances are that you've not written it yourself, but have borrowed the code from a third party. Take Netscape's Hitometer for example, a remotely hosted application that looks like it's running from your own website, but is in fact entirely resident and executing on Netscape's servers.

Search engines on most websites are also normally operated by ASPs.

Other remotely-hosted web utilities include those from @manage, which can remotely monitor every aspect of your URLs and deliver regular performance results - great to see if your web hosting services are up to scratch. Then there's ecommerce services that provide your website with shopping facilities up front, but sort out all the secure credit card transactions remotely without you having to acquire merchant status.

You don't have to use the apps offered by the ASP. Perhaps there's a particular specialised application you need to use, but don't wish to deploy personally. Many ASPs offer dedicated hosting of applications of your own choice.

Then there's alternative hosted services that aren't really traditional applications as we know them. How about using an ASP to outsource actual security, such as the often resource-intensive task of maintaining a sophisticated firewall? eSoft Global is a European ASP that offers such security services along with traditional application hosting.

NetStore, another European ASP, offers hosting of Exchange 2000 Server, but also an innovative internet backup service. Offsite backing up of data has always been a sensible way of protecting information even if your own offices go up in smoke. But rather than physically posting disks, or making dedicated connections to the secure offsite location, NetStore allows you to back up to its secure servers over the internet.

The beauty of internet backup is that you can perform the small incremental updates whenever you're online in a matter of seconds. If the worst happens and you lose your data, simply download and reinstall NetStore's 1.11Mb client and access your information once again - it can even post your data on a CD for £49.99 including overnight delivery.

The big issues
You've heard about the theory behind ASPs, but what about the issues in practice? The biggest fear for all users of ASPs will understandably be that either the ASP's own servers or the link across the internet fails or even just reduces in speed, rendering them helpless or at least less useful. This is where quality of service (QoS) comes in.

The reason most ASPs don't list prices on their websites is that they're negotiable depending on the all-important service level agreement (SLA). This is a contract between the ASP and the client, listing guaranteed and understood levels of performance, availability and support - the QoS in other words - for an agreed price.

Clearly the ASPs want to ensure their own network connections are reliable, and many will do so by also being their own ISPs. Conversely many ISPs (particularly those offering broadband connections) will offer application hosting as a value-added service. Whoever is providing your apps and by whatever means, it's essential to agree on an SLA that provides what you require.

Then there's the ownership of data and apps. If one ASP is hosting your customised applications and documents but falls out of favour, just how easy will it be to switch to another provider? Again, the SLA should cover contract periods, renewals and changing providers.

Reduce the hassle
It's certainly an exciting time, where in the near future we could be accessing graphically rich powerful 32bit applications on all manner of cheap and simple information appliances. We may never have to worry about the pain of upgrading software or hardware to just get at that new killer feature. Mobile workers and owners of multiple devices will easily be able to access their information anywhere.

ASPs are certainly going to be huge and all the analysts agree: IDC believes hosting is set to grow significantly over the next few years, Forrester Research projects the market for leased applications will reach $6.4bn annually by 2001, and DataQuest reckons it will hit $22bn by 2003.

As soon as broadband always-on (ADSL) connections make their way into homes and small businesses, a new market of users will be able to enjoy hosted services. Head over to the application service section of eSoft and download the Citrix ICA client for your device to try out a fully functional Windows 2000 desktop loaded up with Office 2000 and other apps. It's surprisingly usable over a modem, but once on ADSL, it's only fractionally behind the performance of a quick PC.

The local processing power of the PC will, of course, still be necessary for highly demanding applications such as desktop publishing, graphics and video editing, but its days could well be numbered for those who mostly use general office applications and email services. Soon end users won't know whether their applications are running locally or remotely, and more importantly, they won't care. Get ready for a hassle-free future.

Bet you're already using an ASP!
Finally, here's something to ponder: believe it or not, we can almost guarantee that you're using an ASP without knowing it. Ever withdrawn money from a cashpoint? Essentially the machine is a thin client accessing a centralised server containing your banking details and the applications required to run the services.

Airline ticketing and check-ins work the same way. These are likely to be connected on a private network, but the server-based computing theory remains.

Have you ever used Hotmail? This is a web-based email service where the application along with all your messages are stored and executed on a remote server accessed over the internet by any client device with a browser. This makes Hotmail the most widespread ASP in the world today.

But soon their will be many tens of thousand more contenders for you to choose from.