add some modules information

building.md

@@ -1,6 +1,7 @@
 <!-- --- title: Building from source -->
 
 [![home](/icons/home.svg "wiki home")](/home)
+[![modules](/icons/layers.svg "modules")](/modules)
 [![packages](/icons/package.svg "packages")](/precompiled)
 
 [[_TOC_]]

home.md

@@ -14,6 +14,7 @@ to the latest version of [OpenFOAM](http://www.openfoam.com).
 | [![readme](/icons/book-open.svg "readme")][foam-readme] [**Readme**][foam-readme] | Further cross-links in the OpenFOAM repository to _system requirements_ etc. |
 | [![repo](/icons/gitlab.svg "repositories")](/page-access-code) [**Access**](/page-access-code) the code | Locations and descriptions of repository branch names |
 | [![build](/icons/cpu.svg "build")](/building) [**Build**](/building) from source | Information about building and links to build or packaging systems |
+| [![modules](/icons/layers.svg "modules")](/modules) [**Modules**](/modules) for OpenFOAM | Additional code modules |
 | [![upgrade](/icons/chevrons-up.svg "upgrade guide")][upgrade-guide] [**Upgrade**][upgrade-guide] guides | User and developer information for upgrading cases and code to more recent releases |
 | [![run](/icons/play.svg "run")](/running) [**Run**](/running) OpenFOAM | Using the OpenFOAM environment |
 | [![download](/icons/download.svg "download")][download-source] [**Download**][download-source] source packs | Download shortcuts |
@@ -21,8 +22,8 @@ to the latest version of [OpenFOAM](http://www.openfoam.com).
 
 ## [![repo](/icons/gitlab.svg "repositories")][all-repos] Repositories
 
-The [develop.openfoam.com site][all-repos] hosts the ***publicly
-accessible*** repositories:
+The [develop.openfoam.com][all-repos] site hosts the
+***publicly accessible*** repositories:
 
 | Repository | Issue tracker |
 |------------|---------------|

icons/layers.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="feather feather-layers"><polygon points="12 2 2 7 12 12 22 7 12 2"></polygon><polyline points="2 17 12 22 22 17"></polyline><polyline points="2 12 12 17 22 12"></polyline></svg>

modules.md

@@ -0,0 +1,118 @@
+<!-- --- title: OpenFOAM Modules -->
+
+[![home](/icons/home.svg "wiki home")](/home)
+[![build](/icons/cpu.svg "build")](/building)
+
+For flexibility and extensibility, OpenFOAM uses [_modules_][all-modules]
+to provide additional functionality.
+There are a variety of different reasons for using modules:
+- inclusion of a larger, ***independent*** code base
+- improve ***isolation*** of third-party ***dependencies***
+- support more ***flexible build*** options
+- ***staging*** functionality that may be later merged into OpenFOAM
+
+Also see related information about git submodules in the
+[modules/README](https://develop.openfoam.com/Development/openfoam/-/tree/develop/modules#git).
+
+
+[[_TOC_]]
+
+## OpenQBMM
+
+[OpenQBMM](OpenQBMM.org) is a suite of solvers to simulate
+polydisperse multiphase flows using Quadrature-Based Moment Methods
+(QBMM) based on OpenFOAM.
+
+***Why a module?***
+
+- retain development, release timing that is independent of the
+  OpenFOAM release schedule.
+- ensure that development changes to OpenFOAM are propagated to
+  OpenQBMM as soon as possible.
+
+
+## adios
+
+The [adios module](https://develop.openfoam.com/Community/adiosfoam)
+provides a function object for checkpointing OpenFOAM using the
+[ADIOS](https://csmd.ornl.gov/software/adios2) library.
+
+***Why a module?***
+
+- isolate library dependencies
+- additional, non-core functionality
+
+
+## avalanche
+
+The [avalanche module](https://develop.openfoam.com/Community/avalache)
+provides libraries, solver and utilities for avalanche modelling using
+finiteArea.
+
+***Why a module?***
+
+- additional, non-core functionality
+- retain independent development
+
+
+## cfmesh
+
+The [cfmesh module](https://develop.openfoam.com/Community/integration-cfmesh)
+is a populate alternative mesher for OpenFOAM.
+
+***Why a module?***
+
+- integration of larger, existing code base
+
+
+## external-solver
+
+The [external solver module](https://develop.openfoam.com/modules/external-solver)
+is primarily an OpenFOAM solver interface to the
+[PETsc](https://www.mcs.anl.gov/petsc/) suite of linear solvers.
+
+***Why a module?***
+
+- isolate library dependencies
+- development timing independent of the OpenFOAM release schedule
+
+
+## visualization
+
+The [visualization module](https://develop.openfoam.com/modules/visualization)
+is a collection of visualization interfaces for OpenFOAM, primarily
+VTK/ParaView based.
+
+Note that the visualization module incorporates some elements which
+were previously part of the OpenFOAM source tree, but have since been
+relocated to module for the improved flexibility and to make the core
+OpenFOAM libraries independent of visualization.
+
+***Why a module?***
+
+- isolate library dependencies
+- support multi-build.
+  Eg, different VTK or ParaView versions, different rendering types etc.
+
+
+### Examples
+
+A [user example](https://develop.openfoam.com/Development/openfoam/-/issues/1848)
+of using the visualization module to add an additional layer to an
+_existing_ OpenFOAM installation (ubuntu docker build):
+
+```
+RUN mkdir -p /home/ofuser/src && \
+    git clone --depth=1 https://develop.openfoam.com/modules/visualization.git \
+    /home/ofuser/src/visualization && \
+    /usr/bin/openfoam2006 -DVTK_DIR=/usr/include/vtk-7.1 \
+        -c '/home/ofuser/src/visualization/Allwmake -prefix=openfoam' ;\
+    rm -rf /home/ofuser/src/visualization
+```
+
+----
+
+Copyright (C) 2020 OpenCFD Ltd.
+
+[all-repos]:    https://develop.openfoam.com/
+[all-modules]:  https://develop.openfoam.com/Development/openfoam/-/tree/develop/modules

page-access-code.md

@@ -1,10 +1,8 @@
 <!-- --- title: Accessing the code -->
 
 [![home](/icons/home.svg "wiki home")](/home)
-
-[[_TOC_]]
-
-## OpenFOAM repositories
+[![modules](/icons/layers.svg "modules")](/modules)
+[![build](/icons/cpu.svg "build")](/building)
 
 OpenFOAM repositories are hosted at the https://develop.openfoam.com webpage.
 Many are **public-access** and can be downloaded or cloned directly;
@@ -15,12 +13,15 @@ features (such as reporting issues), users must create an account.
 |------------|---------------|
 | [OpenFOAM][foam-repo] | [issues][foam-issues] |
 | [ThirdParty][third-repo] build scripts | [issues][third-issues] |
+| Additional [modules][all-modules] | _individual_ |
 
 _If you have been using the [older OpenFOAM git repository][old-foam-repo] (prior to DEC-2019)
 and have code you need to migrate, you should see the [repository migration](Repository-migration) information._
 
 
-### Organization of git branches
+[[_TOC_]]
+
+## Organization of git branches
 
 OpenFOAM follows a
 [branching workflow](https://git-scm.com/book/en/v2/Git-Branching-Branching-Workflows)
@@ -43,6 +44,9 @@ Since they will also occasionally be rebased onto the lastest
 `develop`, there is ***no*** guarantee of continuity.
 
 
+## Additional Information
+
+
 ### Exploring projects
 
 - From the projects menu you can navigate through various projects as shown below.
@@ -149,6 +153,8 @@ multiple SSH keys and distinguish them with proper title.
 
 Copyright (C) 2019-2020 OpenCFD Ltd.
 
+[all-repos]:    https://develop.openfoam.com/
+[all-modules]:  https://develop.openfoam.com/Development/openfoam/-/tree/develop/modules
 
 [foam-repo]:    https://develop.openfoam.com/Development/openfoam/
 [third-repo]:   https://develop.openfoam.com/Development/ThirdParty-common/

precompiled.md

@@ -1,6 +1,7 @@
 <!-- --- title: Precompiled Packages -->
 
 [![home](/icons/home.svg "wiki home")](/home)
+[![modules](/icons/layers.svg "modules")](/modules)
 [![build](/icons/cpu.svg "build")](/building)
 [![running](/icons/play.svg "running")](/running)