memcached!

Varnish Cache is an open source, state of the art HTTP application accelerator. You can install it on your HTTP server and it makes your application more accessible.

Orchestrate Real Apps on the Cloud with CloudifyAchieve a smooth transition to the cloud and easy automation of even the most complex applications throughout their entire lifecycle with Cloudify. Orchestrate the creation of the whole cloud infrastructure required for your application, starting from compute resources all the way down to networks and block storage devices. Cloudify will then deploy your applications to the cloud (OpenStack, VMWare vSphere, or even bare metal like Softlayer), monitor their progress and scale them when needed. »

Couchbase is the NoSQL database market share leader, with production deployments at AOL, Deutsche Post, NTT Docomo, Salesforce.com, Turner Broadcasting Systems, Zynga and hundreds of other organizations worldwide. Couchbase products enable a more flexible, scalable, high-performance, and cost-effective approach to data management than relational database solutions and are particularly well suited for web applications deployed on virtualized or cloud infrastructures, and mobile applications requiring real-time data synchronization between devices and the cloud. Couchbase is a privately held company funded by Accel Partners, Ignition Partners, Mayfield Fund and North Bridge Venture Partners. www.couchbase.com »

Hazelcast is an in-memory Open Source data grid based on Java. By having multiple nodes form a cluster, data is evenly distributed among the nodes. This allows for horizontal scalability both in terms of available storage space and processing power. Backups are also distributed in a similar fashion to other nodes, based on configuration, thereby protecting against single node failure.

The GridGain In-Memory Data Fabric is a proven software solution, which enables high-performance transactions, real-time streaming and fast analytics in a single, comprehensive data access and processing layer. The In-Memory Data Fabric is designed to easily power both existing and new applications in a distributed, massively parallel architecture on affordable, industry-standard hardware.

HyperDex is the next generation key-value store. It provides a rich API, strong consistency, fault-tolerance, and transactions.

Apache Ignite In-Memory Data Fabric is a high-performance, integrated and distributed in-memory platform for computing and transacting on large-scale data sets in real-time, orders of magnitude faster than possible with traditional disk-based or flash technologies.Apache Ignite In-Memory Data Fabric is designed to deliver uncompromised performance for a wide set of in-memory computing use cases from high performance computing, to the industry most advanced data grid, highly available service grid, and streaming. »

Cachelot works within a fixed amount of memory. No garbage collector. Small metadata, near perfect memory utilization (overhead is 5-7% of the total memory).Smooth responsiveness, without any "gaps" for both read and write operations. Most operations have O(1) complexity.Can be used as a library or as a stand-alone memcached server.

XCache is a fast, stable PHP opcode cacher that has been tested and is now running on production servers under high load. It is tested on Linux and FreeBSD and supported under Windows, for thread-safe and non-thread-safe versions of PHP. This relatively new opcode caching software has been developed by mOo, one of the developers of Lighttpd, to overcome some of the limitations of the existing solutions at that time; such as being able to use it with new PHP versions as they arrive.

Open Source .NET Distributed Cache!

The APC (Alternative PHP Cache) is an Open Source opcode cache extension to the PHP programming language server daemon.

eAccelerator is a free open-source PHP accelerator & optimizer. It increases the performance of PHP scripts by caching them in their compiled state, so that the overhead of compiling is almost completely eliminated. It also optimizes scripts to speed up their execution. eAccelerator typically reduces server load and increases the speed of your PHP code by 1-10 times.

Tarantool is a NoSQL database management system running in a Lua application server. The code is available for free under the terms of BSD license. Supported platforms are GNU/Linux, Mac OS and FreeBSD.

Infinispan is a distributed in-memory key/value data store with optional schema, available under the Apache License 2.0. It can be used both as an embedded Java library and as a language-independent service accessed remotely over a variety of protocols (HotRod, REST, Memcached and WebSockets). It offers advanced functionality such as transactions, events, querying and distributed processing.