• Add Graal JIT Compilation to Your JVM Language in 5 Steps, A Tutorial http://stefan-marr.de/2015/11/add-graal-jit-compilation-to-your-jvm-language-in-5-easy-steps-step-1/

• The SimpleLanguage, an example of using Truffle with great JavaDocs https://github.com/graalvm/simplelanguage

• Truffle Tutorial, Christan Wimmer, PLDI 2016, 3h recording https://youtu.be/FJY96_6Y3a4 Slides

• Series of blog posts on implementing a Lisp http://cesquivias.github.io/

• Truffle Tutorials, Presentations, Publications https://github.com/graalvm/graal/blob/master/docs/Publications.md

• Graal VM and Graal.JS on the Oracle Technology Network http://www.oracle.com/technetwork/oracle-labs/program-languages/overview/index-2301583.html

• Papers on Truffle http://ssw.jku.at/Research/Projects/JVM/Truffle.html

• Papers on Graal http://ssw.jku.at/Research/Projects/JVM/Graal.html

Maintained

• FastR, an R implementation: https://github.com/graalvm/fastr
• TruffleRuby: https://github.com/graalvm/truffleruby
• SOM Smalltalk: https://github.com/SOM-st/TruffleSOM
• SOMns, a Newspeak: https://github.com/smarr/SOMns
• SimpleLanguage: https://github.com/graalvm/simplelanguage
• Graal.JS, a JavaScript implementation: http://www.oracle.com/technetwork/oracle-labs/program-languages/overview/index-2301583.html
• Sulong, a LLVM IR implementation on top of the JVM https://github.com/graalvm/sulong

Status Unknown:

• ZipPy, a Python 3: https://bitbucket.org/ssllab/zippy

Experiments

• TruffleSqueak, Squeak interpreter on top of Truffle https://github.com/timfel/trufflesqueak

• TruffleC, a C on top of the JVM: http://dl.acm.org/citation.cfm?id=2647528

• Mumbler: A Lisp https://github.com/cesquivias/mumbler & http://cesquivias.github.io/

• Lua https://github.com/lucasallan/LuaTruffle & http://www.luatruffle.org/

• Hex https://bitbucket.org/hexafraction/truffles & https://hextruffle.wordpress.com/

• Golo (a minimal Truffle backend) https://github.com/smarr/golo-lang/tree/truffle

• TruffleMATE, a Smalltalk with a completely reified runtime system https://github.com/charig/TruffleMATE

• PureScript https://github.com/slamdata/truffled-purescript

• Mozart/Oz https://github.com/eregon/mozart-graal

• DynSem: A Language Specification-Language, as a meta-interpreter in Truffle https://github.com/metaborg/dynsem

• Cover: A Safe Subset of C++ https://github.com/gerard-/cover

• TrufflePascal https://github.com/Aspect26/TrufflePascal/

• Reactive Ruby: Truffle Ruby meets Reactive Programming https://github.com/guidosalva/ReactiveRubyTruffle

• PorcE: An Orc implementation on top of Truffle https://github.com/orc-lang/orc/tree/master/PorcE

• shen-truffle https://github.com/ragnard/shen-truffle

• The Truffle paper: “Self-Optimizing AST Interpreters” http://lafo.ssw.uni-linz.ac.at/papers/2012_DLS_SelfOptimizingASTInterpreters.pdf

• How to represent Objects Efficiently: “An Object Storage Model for the Truffle Language Implementation Framework” http://chrisseaton.com/rubytruffle/pppj14-om/pppj14-om.pdf

• The Truffle+Graal paper: "One VM to Rule Them All" http://lafo.ssw.uni-linz.ac.at/papers/2013_Onward_OneVMToRuleThemAll.pdf

• The Partical Evaluation paper: "Practical partial evaluation for high-performance dynamic language runtimes"
  accessible via: http://www.sigplan.org/OpenTOC/pldi17.html or https://doi.org/10.1145/3062341.3062381

• One Compiler: Deoptimization to Optimized Code (work on SubstrateVM, AOT compilation of Truffle code) http://doi.org/10.1145/3033019.3033025