diff --git a/.github/ISSUE_TEMPLATE/config.yml b/.github/ISSUE_TEMPLATE/config.yml
index 907121f858..9ceaab2ae7 100644
--- a/.github/ISSUE_TEMPLATE/config.yml
+++ b/.github/ISSUE_TEMPLATE/config.yml
@@ -5,7 +5,7 @@ contact_links:
     about: A new major feature should be discussed in the Zarr specifications repository.
   - name: ❓ Discuss something on Zulip
     url: https://ossci.zulipchat.com/
-    about: For questions like "How do I do X with Zarr?", you can move to our Gitter channel.
+    about: For questions like "How do I do X with Zarr?", you can move to our Zulip Chat.
   - name: ❓ Discuss something on GitHub Discussions
     url: https://github.com/zarr-developers/zarr-python/discussions
     about: For questions like "How do I do X with Zarr?", you can move to GitHub Discussions.
diff --git a/.github/workflows/releases.yml b/.github/workflows/releases.yml
index 250c6112c8..6d417042b5 100644
--- a/.github/workflows/releases.yml
+++ b/.github/workflows/releases.yml
@@ -64,7 +64,7 @@ jobs:
         with:
           name: releases
           path: dist
-      - uses: pypa/gh-action-pypi-publish@v1.8.11
+      - uses: pypa/gh-action-pypi-publish@v1.8.12
         with:
           user: __token__
           password: ${{ secrets.pypi_password }}
diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index 08cac8d78d..e45cae1b45 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -16,4 +16,6 @@ python:
       extra_requirements:
         - docs
 
-formats: all
+formats:
+  - htmlzip
+  - pdf
diff --git a/README.md b/README.md
index b035ffa597..e379c9719f 100644
--- a/README.md
+++ b/README.md
@@ -70,10 +70,10 @@
   </td>
 </tr>
 <tr>
-	<td>Gitter</td>
+	<td>Zulip</td>
 	<td>
-		<a href="https://gitter.im/zarr-developers/community">
-		<img src="https://badges.gitter.im/zarr-developers/community.svg" />
+		<a href="https://ossci.zulipchat.com/">
+		<img src="https://img.shields.io/badge/zulip-join_chat-brightgreen.svg" />
 		</a>
 	</td>
 </tr>
diff --git a/docs/index.rst b/docs/index.rst
index 06f79b7e7c..cf54e261af 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -19,13 +19,13 @@ Zarr-Python
 
 **Version**: |version|
 
-**Download documentation**: `PDF/Zipped HTML/EPUB <https://readthedocs.org/projects/zarr/downloads/>`_
+**Download documentation**: `PDF/Zipped HTML <https://readthedocs.org/projects/zarr/downloads/>`_
 
 **Useful links**:
 `Installation <installation.html>`_ |
 `Source Repository <https://github.com/zarr-developers/zarr-python>`_ |
 `Issue Tracker <https://github.com/zarr-developers/zarr-python/issues>`_ |
-`Gitter <https://gitter.im/zarr-developers/community>`_
+`Zulip Chat <https://ossci.zulipchat.com/>`_
 
 Zarr is a file storage format for chunked, compressed, N-dimensional arrays based on an open-source specification.
 
diff --git a/requirements_dev_optional.txt b/requirements_dev_optional.txt
index 85f6fccffc..0f4493b1d4 100644
--- a/requirements_dev_optional.txt
+++ b/requirements_dev_optional.txt
@@ -8,14 +8,14 @@ ipywidgets==8.1.2
 # don't let pyup change pinning for azure-storage-blob, need to pin to older
 # version to get compatibility with azure storage emulator on appveyor (FIXME)
 azure-storage-blob==12.16.0 # pyup: ignore
-redis==5.0.1
+redis==5.0.2
 types-redis
 types-setuptools
 pymongo==4.6.2
 # optional test requirements
 coverage
 pytest-cov==4.1.0
-pytest-doctestplus==1.1.0
+pytest-doctestplus==1.2.0
 pytest-timeout==2.2.0
 h5py==3.10.0
 fsspec==2023.12.2