Work on structure + Getting started is reworked

doc/book/src/intro.md

@@ -10,17 +10,17 @@ To promote better data management policies, with focused on the following desira
   - **Self-contained & lightweight**: works everywhere and integrates well in existing environments to target hyperconverged infrastructures
   - **Highly resilient**: highly resilient to network failures, network latency, disk failures, sysadmin failures
   - **Simple**: simple to understand, simple to operate, simple to debug
-  - **Internet enabled**: Made for multi-sites (eg. datacenter, offices, etc.) interconnected through a regular internet connection.
+  - **Internet enabled**: made for multi-sites (eg. datacenter, offices, etc.) interconnected through a regular internet connection.
 
 We also noted that the pursuit of some other goals are detrimental to our initial goals.
 The following have been identified has non-goals, if it matters to you, you should not use Garage:
 
-  - **Extreme performances**: high performances constrain a lot the design and the deployment. We always prioritize 
-  - **Feature extensiveness**: Complete implementation of the S3 API
-  - **Storage optimizations**: Erasure coding (our replication model is simply to copy the data as is on several nodes, in different datacenters if possible)
-  - **POSIX/Filesystem compatibility**: We do not aim at being POSIX compatible or to emulate any kind of filesystem. Indeed, in a distributed environment, such syncronizations are translated in network messages that impose severe constraints on the deployment.
+  - **Extreme performances**: high performances constrain a lot the design and the infrastructure; we seek performances through minimalism only.
+  - **Feature extensiveness**: complete implementation of the S3 API or any other API to make garage a drop-in replacement is not targeted as it could lead to decisions impacting our desirable properties.
+  - **Storage optimizations**: erasure coding or any other coding technique both increase the difficulty of placing data and synchronizing; we limit ourselves to duplication.
+  - **POSIX/Filesystem compatibility**: we do not aim at being POSIX compatible or to emulate any kind of filesystem. Indeed, in a distributed environment, such syncronizations are translated in network messages that impose severe constraints on the deployment.
 
-## Integration in environments
+## Supported and planned protocols
 
 Garage speaks (or will speak) the following protocols:
 
@@ -36,9 +36,9 @@ We plan to add logic to Garage to make it a viable solution for email storage.
 Especially, it is used to host their main website, this documentation and some of its members's blogs. Additionally,
 Garage is used as a [backend for Nextcloud](https://docs.nextcloud.com/server/20/admin_manual/configuration_files/primary_storage.html). Deuxfleurs also plans to use Garage as their [Matrix's media backend](https://github.com/matrix-org/synapse-s3-storage-provider) and has the backend of [OCIS](https://github.com/owncloud/ocis).
 
-*Are you using Garage? Open a pull request to add your organization here!*
+*Are you using Garage? [Open a pull request](https://git.deuxfleurs.fr/Deuxfleurs/garage/) to add your organization here!*
 
-## Comparisons to existing software
+## Comparison to existing software
 
 **[Minio](https://min.io/) :** Minio shares our *self-contained & lightweight* goal but selected two of our non-goals: *storage optimizations* through erasure coding and *POSIX/Filesystem compatibility* through strong consistency.
 However, by pursuing these two non-goals, minio do not reach our desirable properties.
@@ -46,17 +46,26 @@ First, it fails on the *simple* property: due to the erasure coding, minio has s
 Second, it fails on the *interned enabled* property: due to its strong consistency, minio is latency sensitive.
 Furthermore, minio has no knowledge of "sites" and thus can not distribute data to minimize the failure of a given site.
 
-**[Openstack Swift](https://docs.openstack.org/swift/latest/)**
+**[Openstack Swift](https://docs.openstack.org/swift/latest/) :**
 OpenStack Swift at least fails on the *self-contained & lightweight* goal.
 Starting it requires around 8Gb of RAM, which is too much especially in an hyperconverged infrastructure.
 It seems also to be far from *Simple*.
 
-**[Pithos](https://github.com/exoscale/pithos)** 
-Pithos has been abandonned and should probably not used yet, in the following we explain why we did not pick their design.
-Pithos was relying as a S3 proxy in front of Cassandra (and was working with Scylla DB too).
-From its designers' mouth, storing data in Cassandra has shown its limitations justifying the project abandonment.
-They built a closed-source version 2 that does not store blobs in the database (only metadata) but did not communicate further on it.
-We considered there v2's design but concluded that it does not fit both our *Self-contained & lightweight* and *Simple* properties. It makes the development, the deployment and the operations more complicated while reducing the flexibility.
+**[Ceph](https://ceph.io/ceph-storage/object-storage/) :**
+This review holds for the whole Ceph stack, including the RADOS paper, Ceph Object Storage module, the RADOS Gateway, etc.
+At is core, Ceph has been designed to provide *POSIX/Filesystem compatibility* which requires strong consistency, which in turn
+makes Ceph latency sensitive and fails our *Internet enabled* goal. 
+Due to its industry oriented design, Ceph is also far from being *Simple* to operate and from being *self-contained & lightweight* which makes it hard to integrate it in an hyperconverged infrastructure.
+In a certain way, Ceph and Minio are closer togethers than they are from Garage or OpenStack Swift.
 
-**[IPFS](https://ipfs.io/)**
-*Not written yet*
+*More comparisons are available in our [Related Work](design/related_work.md) chapter.*
+
+## Community
+
+If you want to discuss with us, you can join our Matrix channel at [#garage:deuxfleurs.fr](https://matrix.to/#/#garage:deuxfleurs.fr).
+Our code and our issue tracker, which is the place where you should report bugs, are managed on [Deuxfleurs' Gitea](https://git.deuxfleurs.fr/Deuxfleurs/garage).
+
+## License
+
+Garage, all the source code, is released under the [AGPL v3 License](https://www.gnu.org/licenses/agpl-3.0.en.html).
+Please note that if you patch Garage and then use it to provide any service over a network, you must share your code!