Nestml

NESTML 5.0.0-rc2 contains several fixes and enhancements compared to rc1.

- It increases the versatility in generating code from different target platforms, by making it easier to use a different set of code generation templates, and extensive internal refactoring of the "printer" classes for elements of the abstract syntax tree.
- It makes the definitions of "inhibitory" and "excitatory" spiking input ports more clear in neuron models.
- Support for running NESTML in Docker was added.
- Fixes running multithreaded in NEST.
- Issues fixed with updated software dependencies (Antlr 4.10), many small bug fixes and documentation updates.

It is currently in **release candidate status**, which means that
- this is the version we recommend you to use;
- we invite feedback, reports and feature requests on the GitHub issue tracker and the NEST-user mailing list;
- for citing this version, we already reserved a DOI: 10.5281/zenodo.5784175
- documentation corresponds to the "5.0.0-rc2" tag on [nestml.readthedocs.org](https://nestml.readthedocs.io/en/v5.0.0-rc2/)

NESTML 5 adds support for synapses and synaptic plasticity rules.

It is currently in **release candidate status**, which means that
- this is the version we recommend you to use;
- we invite feedback, reports and feature requests on the GitHub issue tracker and the NEST-user mailing list;
- for citing this version, we already reserved a DOI: 10.5281/zenodo.5784175
- documentation corresponds to the "5.0.0-rc1" tag on [nestml.readthedocs.org](https://nestml.readthedocs.io/en/v5.0.0-rc1/)

[NESTML 4.0](https://doi.org/10.5281/zenodo.4740083) contains many fixes, enhancements in user experience, and updates for the newest NEST 3.0 API.

- ``shape`` was renamed to ``kernel``
- Higher-order kernels have to be formulated in a mathematically consistent format: the old ``g'=...``, ``g''=...`` is no longer allowed; the second variable should be renamed to a helper variable, e.g. ``g'=...``, ``h'=...``. Please see [the NESTML language documentation](https://nestml.readthedocs.io/en/v4.0/nestml_language.html) on how to formulate kernels of any order.
- All blocks (``state``, ``update``, ``input``, ``output``) were made optional. This means that any empty blocks that were added just to satisfy the parser, can now be removed.
- Removed ``initial_values`` block; this functionality was already provided by the ``state`` block.
- Parameters and internals (internal, derived parameter values) are no longer recordable for efficiency reasons.
- ``current`` type input and output ports renamed to ``continuous``

[NESTML 3.1](https://dx.doi.org/10.5281/zenodo.3697733) contains many fixes, enhancements in user experience, and updates for the newest NEST 3.0 API.

This is the first release based on the Python rewrite of NESTML.