Open Cloud Platform

PHP
Orchestra (http://orchestra.io /)
Cloud control (http://cloudcontrol.com /)
Bitnami cloud (http://bitnami.org/cloud)
Relb( http://relbit.com /)
Microsoft Azure (http://www.microsoft.com/windowsazure)
Php fog (https://www.phpfog.com/)-invite only (for invitation only)
Makara (http://www.makara.com/)-Developer Preview (developer visible)
Dotcloud-(http://www.dotcloud.com/)-invite only (for invitation only)

Python
App Engine (http://code.google.com/appengine)
Deployfu (http://www.deployfu.com /)
Picture( http://www.picloud.com /)
Djangozoom (http://djangozoom.com/)-invite only (for invitation only)
Nuage (http://www.nuagehq.com/)-invite only (for invitation only)
Ep. io (http://www.ep.io/)-invite only (for invitation only)
Apphosted (https://apphosted.com/)-private beta (private beta)
Gondor (https://gondor.io/)-private beta (private Beta)
Dotcloud-(http://www.dotcloud.com/)-invite only (for invitation only)
Stable. io (http://stable.io/)-invite only (for invitation only)
Pydra (http://www.pydra.com/)-invite only (for invitation only)

Ruby
Heroku (http://www.heroku.com /)
BitNami Cloud (http://bitnami.org/cloud)
EngineYard (http://www.engineyard.com /)
Duostack (https://www.duostack.com/)-open beta (Public Beta)
Cloud Foundry (http://www.cloudfoundry.com/)-invite only (for invitation only)
Dotcloud-(http://www.dotcloud.com/)-invite only (for invitation only)
Railscloud (https://www.railscloud.de/)-beta (Beta)

Java
App Engine (http://code.google.com/appengine)
BitNami Cloud (http://bitnami.org/cloud)
CloudBees (http://www.cloudbees.com /)
Microsoft Azure (http://www.microsoft.com/windowsazure)
Makara (http://www.makara.com/)-developer preview
Amazon Elastic Beanstalk (http://aws.amazon.com/elasticbeanstalk/)-beta (Beta)
CumuLogic (http://www.cumulogic.com/)-beta (Beta)
Cloud Foundry (http://www.cloudfoundry.com/)-invite only (for invitation only)
Dotcloud-(http://www.dotcloud.com/)-invite only (for invitation only)

Node JS
DeployFu (http://www.deployfu.com /)
JoyentCloud (https://no.de /)
Nodester (http://nodester.com/)-invite only (for invitation only)
Nodejitsu (http://www.nodejitsu.com/)-private beta (private Beta)
Duostack (https://www.duostack.com/)-open beta (Public Beta)
Cloud Foundry (http://www.cloudfoundry.com/)-invite only (for invitation only)
Dotcloud-(http://www.dotcloud.com/)-invite only (for invitation only)
NodeSocket (http://www.nodesocket.com/)-invite only (for invitation only)
Cloudnode (http://cloudno.de/)-in development (under development)

. NET
Appharmacy (https://appharbor.com /)
DeployFu (http://www.deployfu.com /)
Microsoft Azure (http://www.microsoft.com/windowsazure)

Perl
Dotcloud-(http://www.dotcloud.com/)-invite only (for invitation only)
Phenona (http://www.phenona.com/)-private beta (private Beta)

Ringo JS
Erbix (http://www.erbix.com /)

Javascript
Akshell (http://www.akshell.com /)