diff --git a/README.md b/README.md
index fb95644..d64c6f4 100644
--- a/README.md
+++ b/README.md
@@ -8,9 +8,11 @@ radiation detectors.
 This material is based upon work supported by the U.S. Department of Energy,
 Office of Science, Nuclear Physics program office under Award Number
 DE-SC0015136.
+
 ## Screenshots
 ![Demo animation](images/software_demo.gif)
 ![RDI logo beam scan](images/screenshot1.png)
+
 ## Tools installation
 The tools include the main `rdi-live` binary.
 1. Install the Go compiler toolchain (version 1.11 or newer) from
@@ -19,3 +21,40 @@ The tools include the main `rdi-live` binary.
 ```shell
 go get github.com/rditech/rdi-live/tools/...
 ```
+
+## Protobuf
+RDI Live uses Protobuf for (de)serialization of event data.  Additionally,
+Protobuf is used to store detector mappings, or metadata that is used to
+related data streams to things like physical layout and calibration.  Finally,
+Protobuf is used for "slow data", or data that are slowly changing compared to
+events, and passed along in the proio streams as stream metadata.  See, e.g.,
+[https://godoc.org/github.com/proio-org/go-proio#Reader](https://godoc.org/github.com/proio-org/go-proio#Reader)
+and [arXiv:1812.03967](https://arxiv.org/abs/1812.03967)).
+
+The Protobuf files that describe the data models for these data are stored
+under the `proto` directory.  Also, Protobuf binaries used for storing detector
+mappings are located in the `detmap` directory.  These files are generated
+elsewhere.  If changes are made to the Protobuf data model files in `proto`,
+the generated source in `model` must be regenerated using `go generate`.  This
+requires the `protoc` command to be installed on your system, as well as a go
+Protobuf compiler plugin.
+
+## Packr
+Executable binaries like `rdi-live` are intended to be completely
+self-contained.  To that end, binaries like detector mappings and web data are
+packaged into the executables using
+[Packr](https://github.com/gobuffalo/packr).  This tool encodes data in certain
+directories in this repository into source code that gets compiled into
+executables when necessary.  For example, Packr is instructed to pack the web
+data into source code
+[here](https://github.com/rditech/rdi-live/blob/master/live/webdata.go),
+resulting in the autogenerated file
+[here](https://github.com/rditech/rdi-live/blob/master/live/a_live-packr.go).
+This makes a highly portable executable, but it also means that any time web
+data or detector mappings are changed, Packr must be called to regenerate
+source code with the new data packed in.  This can be by first installing the
+`packr` tool, and then running
+```shell
+packr -z
+```
+in the root directory of the repository.