We could only find support for hosted Windows (Windows 7 and Windows 2008R2 "terminal") sessions. You can't find Mac OS because of Apple's licensing constraints, and hosted Linux sessions are difficult to find.
In terms of productivity applications, most of the vendors could supply Microsoft Office and SharePoint. They also expressed a willingness to brand DaaS desktops with organizational logos, "stock" applications and resource links, as well as to negotiate preloaded software for both persistent and ad hoc sessions.
How DaaS works
In the simplest form, DaaS is like Remote Desktop Protocol (RDP), Virtual Network Control (VNC), and similar provisioning that dates back to the the PCAnywhere days, where you got screen, keyboard, and mouse (at minimum) connected to another computer, so as to use that system as though you were sitting comfortably nearby.
Today's iteration is Virtual Device Interface-Infrastructure (VDI), which includes the basics, plus sound, local drive, and local ports (like USB). VDI can be accomplished on premise or in the cloud.
DaaS service providers are the gateway for cloud-based connectivity, which includes virtualized desktop sessions and applied administrative constraints. The selling points are hosted external applications, shared storage resources, joining DaaS resources as extensions of an existing (or new) Active Directory infrastructure, and extended device compatibility in a BYOD scenario.
Here are the individual reviews:
Desktone uses Citrix components mixed with its own desktop portal and management infrastructure. The Citrix pieces, including session access applications like Citrix Receiver, give remote users choices for what kind of device, such as a Mac or a Windows XP client, might be compatible with a Desktone-hosted Windows7 session.
Hosted sessions can reside in an isolated Active Directory or workgroup environment, or could be connected via a VPN (many types are supported) linking Desktone's provisioned desktops and network with a customer network.
VPN connectivity can be problematic because of the varying types of VPNs possible. Those connected with firewall and VPN appliances are said to be the most easily (and quickly) deployed.