Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!
Open Neural Network Exchange (ONNX)
https://github.com/onnx
https://github.com/onnx/onnxmltools
Predictive Model Markup Language (PMML)
https://github.com/jpmml/sklearn2pmml
PMML4S is a PMML (Predictive Model Markup Language) scoring library for Scala. It provides both Scala and Java Evaluator API for PMML.
JPMML-Evaluator is a Java evaluator API for PMML.
[Plain Old Java Object (POJO)]
H2O supports exporting models into POJO (JAR) files.
MLeap
Pickle
Some Python libraries support serializaing a model into pickle format.
Save and Load Models in PyTorch
https://pytorch.org/docs/stable/notes/serialization.html#recommend-saving-models
PyTorch -> ONNX -> TensorFlow
https://github.com/onnx/onnx-tensorflow/issues/491
https://towardsdatascience.com/converting-a-simple-deep-learning-model-from-pytorch-to-tensorflow-b6b353351f5d