Choose bobview or bobview-ssh

bobview draws with OpenGL. Two commands start it:

command	draws with	use it
`bobview`	the machine's own OpenGL: the GPU, or whatever driver the desktop provides	normally: on a local desktop, a laptop, a Mac, the phone
`bobview-ssh`	Mesa in software, on the CPU of the machine bobview runs on	when the OpenGL path can't work, such as over `ssh -X`

Both take the same arguments. Start with bobview, and switch to bobview-ssh if it fails to start or draws nothing.

When to use bobview-ssh

Over ssh -X or -Y. This is what it was named for. Forwarded OpenGL reaches your local X server as indirect GLX, which current X servers refuse, so bobview exits with glutin error: [2] BadValue.
Where a GPU driver is installed but can't be used, for example a remote desktop, VNC or Xvfb session on a machine with an NVIDIA driver: glvnd picks NVIDIA's GL, which then has no GPU display to draw on.
Where the GPU driver is broken or misbehaves, as a workaround while you sort it out.

There is no need for it on macOS, on Wayland or X11 desktops with working graphics, in the Android Linux Terminal, or for --snapshot, unless one of the cases above applies.

What it does

bobview-ssh is a small script that runs bobview with:

LIBGL_ALWAYS_SOFTWARE=1, so Mesa renders on the CPU (llvmpipe);
__GLX_VENDOR_LIBRARY_NAME=mesa, and __EGL_VENDOR_LIBRARY_FILENAMES pointing at Mesa's EGL vendor file, so libglvnd picks Mesa rather than a GPU vendor's library such as NVIDIA's.

Over X forwarding the finished window then travels to your X server as plain images, which every X server accepts.

Software rendering costs CPU on the machine running bobview, but bobview's displays are simple to draw, so it is usually quick enough. Over ssh -X each redraw sends the whole window over the network, so bobview redraws a window only for its own input and when a PV it shows changes, at most 10 times a second (see Pinned windows and the viewer).

Requirement

Mesa must be installed where bobview runs: mesa-dri-drivers on RHEL, libgl1-mesa-dri on Debian and Ubuntu (both are in the install prerequisites).

Example

ssh -X control-host
bobview-ssh /path/to/screen.bob -m P=BL01T

Layouts restore window positions over X forwarding; see Save and restore a layout.