diff --git a/README.md b/README.md
index 2235754..d0539a1 100644
--- a/README.md
+++ b/README.md
@@ -47,13 +47,33 @@ act -j test
 # Run in dry-run mode:
 act -n
 
-# Run in reuse mode to save state:
-act -r
-
 # Enable verbose-logging (can be used with any of the above commands)
 act -v
 ```
 
+# Platforms
+GitHub Actions offers managed [virtual environments](https://help.github.com/en/actions/reference/virtual-environments-for-github-hosted-runners) for running workflows.  In order for `act` to run your workflows locally, it must run a container for the runner defined in your workflow file.  Here are the images that `act` uses for each runner type:
+
+| GitHub Runner   | Docker Image |
+| --------------- | ------------ |
+| ubuntu-latest   | [ubuntu:18.04](https://hub.docker.com/_/ubuntu) |
+| ubuntu-18.04    | [ubuntu:18.04](https://hub.docker.com/_/ubuntu) |
+| ubuntu-16.04    | [ubuntu:16.04](https://hub.docker.com/_/ubuntu) |
+| windows-latest  | `unsupported` |
+| windows-2019    | `unsupported` |
+| macos-latest    | `unsupported` |
+| macos-10.15     | `unsupported` |
+
+These default images do not contain all the tools that GitHub Actions offers by default in their runners.  If you need an environment that works just like the corresponding GitHub runner then consider using an image provided by [nektos/act-environments](https://github.com/nektos/act-environments):
+
+* [nektos/act-environments-ubuntu:18.04](https://hub.docker.com/r/nektos/act-environments-ubuntu/tags) - built from the Packer file GitHub uses in [actions/virtual-environments](https://github.com/actions/runner).
+
+To use a different image for the runner, use the `-P` option:
+
+```
+act -P ubuntu-latest=nektos/act-environments-ubuntu:18.04
+```
+
 # Secrets
 
 To run `act` with secrets, you can enter them interactively or supply them as environment variables. The following options are available for providing secrets:
diff --git a/cmd/input.go b/cmd/input.go
index cfb9134..63a64ad 100644
--- a/cmd/input.go
+++ b/cmd/input.go
@@ -15,7 +15,7 @@ type Input struct {
 	platforms       []string
 	dryrun          bool
 	forcePull       bool
-	logOutput       bool
+	noOutput        bool
 }
 
 func (i *Input) resolve(path string) string {
diff --git a/cmd/root.go b/cmd/root.go
index 484cb39..a22b10f 100644
--- a/cmd/root.go
+++ b/cmd/root.go
@@ -38,7 +38,7 @@ func Execute(ctx context.Context, version string) {
 	rootCmd.PersistentFlags().StringVarP(&input.workflowsPath, "workflows", "W", "./.github/workflows/", "path to workflow files")
 	rootCmd.PersistentFlags().StringVarP(&input.workdir, "directory", "C", ".", "working directory")
 	rootCmd.PersistentFlags().BoolP("verbose", "v", false, "verbose output")
-	rootCmd.PersistentFlags().BoolVarP(&input.logOutput, "output", "o", false, "log output from steps")
+	rootCmd.PersistentFlags().BoolVarP(&input.noOutput, "quiet", "q", false, "disable logging of output from steps")
 	rootCmd.PersistentFlags().BoolVarP(&input.dryrun, "dryrun", "n", false, "dryrun mode")
 	if err := rootCmd.Execute(); err != nil {
 		os.Exit(1)
@@ -97,7 +97,7 @@ func newRunCommand(ctx context.Context, input *Input) func(*cobra.Command, []str
 			ForcePull:       input.forcePull,
 			ReuseContainers: input.reuseContainers,
 			Workdir:         input.Workdir(),
-			LogOutput:       input.logOutput,
+			LogOutput:       !input.noOutput,
 			Secrets:         newSecrets(input.secrets),
 			Platforms:       input.newPlatforms(),
 		}