>>>You don't mention the type of app but since you are currently on VFP I'd assume a standard desktop type of affair? If that's that
>>>case then .NET could well be a good choice. But you would need to choose between WinForms and WPF. OTOH, depending on
>>>the app, it might be a good time to consider an Intra/Internet based approach - in which case there's a much bigger choice.
>
>We have a vertical market core application, installed in a little over 100 clients. It's a Windows Forms application with VFP back end.
>We also sell a number of separate companion applications which use the same in house framework.
>
>70%+ of our clients are small businesses with 1-5 workstations, single PC, peer2peer and server based networks. we have some larger clients 20+ workstations and 2 clients on Citrix WAN, all clients use exactly the same version of the system and we provide free upgrades to keep them all on a single code base.
>
>The smaller clients have little or no in-house IT, so management of SQL-Server does worry me.

What's the largest DB you have to accommodate?

>Our clients are geographically spread around the UK and many have very poor internet access so SaaS may have some issues.

I guess that rules out a one-size-fits-all solution..

I'm currently involved in the re-write of a VFP/VB app with ~4000 users but the user mix is pretty similar to yours. About 60% of users currently have (or, strictly speaking, are *allowed*) internet access but that figure is assumed to increase with time. At the moment we're experimenting with a WPF solution using ClickOnce and cloud based data storage which is looking good for those with internet access. The app is fairly unusual in that the users data requirements are normally not more than a few hundred records in a small number of tables so for those *without* internet access we should be able to get by using MSSQL CE and a few small changes in the DA layer.....