Avatars United 0.8.1 

0.8.1

http://developer.avatarsunited.com/

Creyle

0.9

http://developer.creyle.jp/

Cyworld

0.9

http://devsquare.nate.com

eBay

0.9

http://developer.ebay.com/products/open-ebay-apps/

Friendster

0.7

http://www.friendster.com/developer

goo Home

0.8.1

http://developer.home.goo.ne.jp/

Google Friend Connect

0.9

http://code.google.com/apis/friendconnect

GROU.PS

0.9

http://grou.ps/groupsdev

hi5

0.8

http://developer.hi5.com/

Hyves

0.7

http://trac.hyves-api.nl/

iGoogle

0.9

http://code.google.com/apis/igoogle/

itimes

0.8

http://www.itimes.com/os_sandbox.php

iWiW

0.9

http://dev.iwiw.hu/

LinkedIn

0.8

http://developer.linkedin.com/index.jspa

Lonely Planet

0.8

http://lplabs.com/groups/

Mixi

http://developer.mixi.co.jp/

MySpace

1.0

http://developer.myspace.com/

Netlog

0.8

http://en.netlog.com/go/developer

Ning

0.8.1

http://developer.ning.com/

orkut

0.8.1

http://sandbox.orkut.com/

PayPal

0.8

https://www.x.com/community/ppx/paypal_apps

Renren

http://dev.renren.com/

Socialtext

0.8

http://www.socialtext.net/open/index.cgi?socialtext_widgets

Sonico

0.8

http://sandbox.sonico.com/app_dev_pres.php

Webjam

0.8.1

http://www.webjam.com/developers/opensocial

Webon

0.8

http://team.webonsites.com/

XING

0.9

https://www.xing.com/net/opensocialpartner

Yahoo!

0.9

http://developer.yahoo.com/yap

vkontakte.ru

http://vkontakte.ru/developers.php

VZ-Netzwerke

1.0

http://www.meinvz.net/Developer

Ametys

Ametys CMS

1.0

http://www.ametys.org/en/telecharger/cms-ametys.html
https://wiki.ametys.org/display/AMETYSV3/Plugin+Gadgets

Alfresco

Alfresco Share

http://www.alfresco.com/products/collaboration/

Atlassian, Inc.

JIRA (Bug Tracker)
Confluence (Enterprise Wiki)

http://www.atlassian.com/software/jira/
http://www.atlassian.com/software/confluence/

BBC

Based on post (http://www.bbc.co.uk/blogs/webdeveloper/2009/11/extending-opensocial-and-shind.shtml) need to get some more details

BNPP
BNP Paribas

Need more details...  Here's a post
[http://qatar.bnpparibas.com/en/news/news.asp?Code=NMES-8FDM4A
]

Cisco

Cisco Quad

http://www.cisco.com/en/US/products/ps10668/index.html

eXo Platform

eXo Portal Product

http://wiki.exoplatform.com/xwiki/bin/view/Portal/

Fatwire (Oracle)

Need to get some more details. Here's their gadget server page (http://www.fatwire.co.uk/products/product/gadgetserver page)

IBM

IBM Rational
Lotuslive

http://jazz.net/
https://www.lotuslive.com/en/

Jive

Jive SBS

1.0

Core Gadgets
Social Gadgets

http://www.jivesoftware.com/products/apps
[http://www.jivesoftware.com/products/engage-customers
]

Liferay

Liferay Portal

1.1

http://www.liferay.com/community/wiki/-/wiki/1071674/Liferay+6.0,%20OpenSocial+and+Gadgets/

Nature Network

Workbench

http://network.nature.com/workbench

SAP

12sprints
SAP Social Network Analyzer (SNA)

http://www.12sprints.com/

Sciverse

SciVerse Hub
ScienceDirect
Scopus

http://www.sciencedirect.com/
http://www.hub.sciverse.com/action/home/proceed
http://www.info.sciverse.com/scopus/

SocialText

Dashboard module

http://www.socialtext.com/products/dashboard.php

SURFNet

Implementing Alfresco

https://wiki.projectbamboo.org/display/BTECH/Open+Social+and+Surfnet+Collaboration

Tibco

Tibber

Need to confirm with Howard W.

WSO2

WSO2 Gadget Server

http://wso2.org/library/gadget-server

Xobni

Xobni Gadgets

http://www.xobni.com/developer/

EurekaStreams

http://www.eurekastreams.org/

Apache Rave

http://incubator.apache.org/rave/

Negroni

http://code.google.com/p/negroni/

Sakai

http://sakaiproject.org/

Gadglet

http://www.gadglet.com/

WidgetPortal

http://www.jbaron.com/software/widgetportal.html