PAAS的开源实现

Eucalyptus
Even if OpenStack has the size and momentum, Eucalyptus is the open source leader in hybrid cloud capability. Eucalyptus lets you build an in-house private cloud that can be driven with the same tools and scripts you use to operate Amazon Web Services. Eucalyptus commands can be used to drive AWS instances too.


This compatibility makes Eucalyptus an excellent development platform and test bed for apps that will be (seamlessly) deployed to AWS and vice versa. New features in Version 3.3 this year include AWS-compatible Auto Scaling, Elastic Load Balancing, and CloudWatch monitoring.


In hybrid scenarios, these new services will allow you to programmatically collect operational metrics from both Amazon and Eucalyptus and shift workloads between the cloud and on-premise as needed.


-- James R. Borck






OpenShift
A free PaaS, OpenShift helps developers build, test, deploy, and manage applications in a cloud. OpenShift incorporates Git and Jenkins, provides Apache and JBoss servers, and supports languages such as Node.js, Ruby, Python, PHP, Perl, and Java. Unlike other open source projects in this space, OpenShift managed to produce a general-availability release. Cloud Foundry may eventually pull ahead with the addition of support from IBM, but this was OpenShift's year in the sun.
提供APACHE和JBOSS服务这样的web容器


-- Michael Scarlett




Cloud Foundry
Cloud Foundry is the open source PaaS offering from the newly formed Pivotal. 


It can be used to deploy your applications on a variety of infrastructures, including Amazon Web Services, OpenStack, and vSphere. It supports Java, Ruby, and Node applications out of the box, but if you're working with .Net, you can use Iron Foundry, another open source project built on Cloud Foundry.
=++++. 看起来，老外说到Paas，作用就在developers build, test, deploy, and manage applications 。如果这个PaaS支持的底层架构多，支持的application容器多，那就是评判好的一个标准。


一般多是看来是从google的分布式系统研究出发的。




MariaDB
MariaDB works as a binary-compatible "drop-in replacement" for MySQL. Databases created in MySQL can be used transparently in MariaDB. The upcoming Version 10.0 of MariaDB backports some changes from MySQL 5.6 and adds features unique to MariaDB, such as the new Cassandra storage engine (for access to Cassandra clusters). What's more, the project is controlled by a foundation that aims to keep MariaDB independent of corporate control -- a safeguard against history repeating the turn that the MySQL project has taken under Oracle.
Cassandra storage engine，也是存储引擎，数据库
-- Serdar Yegulalp




Neo4j
An agile and blazing-fast graph database, Neo4j can be used in a variety of different ways, including social applications, recommendation engines, fraud detection, resource authorization, and data center network management. Neo4j has continued its steady progress with both performance improvements (streaming of query results) and improved clustering/HA support.


-- Michael Scarlett
Salt
What's important when managing massive numbers of servers? Speed and simplicity. SaltStack achieves both in solving the two biggest problems in server management: remote command execution and configuration management. Everything from FreeBSD jails to Amazon EC2 Amazon Machine Images can be managed from a single UI, eliminating the need for multiple management interfaces. The project is relatively new, so the code and architecture are clean, and SaltStack seems to have gathered a good (egoless) community around it.
管理外围物理机器