Here is a list of good Hyper-V Tools. Some of them also gives you the ability to use them with Citrix XenServer, since they are based on the VHD image format.

Wim2VHD

Creates a Windows Server 2008/Vista/Win7 VHD from media in 5 minutes.

VHDtool

Command-line tool for VHD manipulation including instant creation of large fixed-size VHDs

Hyper-V PowerShell library

PowerShell Library for Hyper-V, simplify Hyper-V scripting

CoreConfigurator

Server Core/Hyper-V Server configuration interface

Hvremote

Configures servers and clients for remote management of Hyper-V in both workgroup and domain environments

nvspbind

Tool for modifying network bindings from the command line

nvspscrub

Tool for removing Hyper-V Virtual Networking Configuration from the parent partition

BootfromUSB-HVS

Simplify the creation of bootable Hyper-V Server USB drives

VM Migration Test Wizard

Discovers which hosts need the “Enable Processor compat” option for Live Migration