Lightroom has the ability to edit an image directly in Photoshop through the Photo menu and then Edit in Photoshop. Look at the next menu item and you see Edit in Other Application. This menu item can be customized to open any software and load the current picture. This includes any third party application or outside software.
Open the Lightroom Preferences and click on the External Editing tab as shown to the left. The second block has a button allowing you to find an executable and attach it as the external application. After choosing one, the menu item changes in Lightroom to indicate the program's name.
I use NeatImage's program for noise removal. I have added it as my external application. Now I can simply pull up an image for development, edit it in NeatImage directly from Photoshop, remove the noise and then finish development. Use whatever common program you use in addition to photoshop and have access from directly within Lightroom.
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