Growl for Windows - Growl for Windows is a Windows-compatible version of https://alternativeto.
Communifire - Enterprise Social Collaboration Software
Notify OSD - Canonicals on-screen-display notification agent, implementing the freedesktop.
LS Intranet - LS Intranet is a corporate intranet that facilitates multiple employees collaborating on projects, and working in synergy.
Notifu - Notifu, a free open source pop-up balloon utility
Unily - Unily is a cloud-based intranet solution designed by SharePoint consultancy BrightStarr.