• up to 10 times faster 100% JDK Serialization compatible drop-in replacement (Ok, might be 99% ..). As an example: Lambda Serialization which came with 1.8 worked instantly.
• Android compatible since version >= 2.17 (use FSTConfiguration.createAndroidDefaultConfiguration() both on server and client side. The configuration object has to be passed into FSTObjectIn/Output constructors)
• OffHeap Maps, Persistent OffHeap maps
• FSTStructs is very similar to IBM's packed objects. Difference is: You can run it with Oracle JDK today.
• optionally en/decode any Serializable object graph to JSON (incl. shared references) (since 2.29) for interop
• Apache 2.0 license since 2.17

Fast JDK-compatible Serialization

Json Serialization

OffHeap + Persistent Maps

MinBin cross platform binary format

Kson: a JSon extension

note: maven.org might lag 1 day behind after releasing.

3.0.0 version (requires java 14, "--add-modules jdk.incubator.foreign" option on compiler and runtime)

<dependency>
    <groupId>de.ruedigermoeller</groupId>
    <artifactId>fst</artifactId>
    <version>3.0.1</version>
</dependency>

2.0 version (java 8)

<dependency>
    <groupId>de.ruedigermoeller</groupId>
    <artifactId>fst</artifactId>
    <version>2.56</version>
</dependency>

jdk1.6 compatible build of fst 2.x

<dependency>
    <groupId>de.ruedigermoeller</groupId>
    <artifactId>fst</artifactId>
    <version>2.48-jdk-6</version>
</dependency>

1.x version (different package name, 1.6 compatible ..). Fixes are not backported anymore, unsupported.

<dependency>
    <groupId>de.ruedigermoeller</groupId>
    <artifactId>fst</artifactId>
    <version>1.63</version>
</dependency>

I am not actively tracking use, maven.org reports more than 14000 downloads from 6000 distinct IP accesses triggered by maven builds world wide per month.

Notable also:

• used in production in Eurex Exchange's trading back end's middleware
• JUptr.io's distributed system / NLP engine uses FST
• Popular Apache Wicket supplementals use FST to speed up Wicket

• master contains dev branch/trunk.
• 1.x contains old version
• The maven build should work out of the box and reproduces the artifact hosted on maven.org
• To use the gradle build, you need to configure the proxy server in settings.properties (or just set empty if you do not sit behind a proxy).

Note that instrumentation done for fst-structs works only if debug info is turned on during compile. Reason is that generating methods at runtime with javassist fails (probably a javassist bug ..). This does not affect the serialization implementation.

JDK 1.6 Build 1.x build since v1.62 are still jdk 6 compatible