Until today I assumed that Meraki was built in-house with only closed source software. But having a look at the Meraki-Firmware-Licenses bundle it is clear that like Unifi Cisco is using many Open Source packages to bring together it's offering:

Having only just gotten my hands wet with Meraki kit I am finding it's far less glitchy than Unifi. That is expected because the Meraki kit is a lot more expensive

Here is a list of the packages referenced in the merak-firmware-licenses.tar it's like a who's who of open source:

base-files
base-passwd
bash
bind
bird2
busybox
bzip2
c-ares
ciscossl
cni
crun
curl
cyrus-sasl
daq
dbus
dhcp
dnscrypt-proxy
dnsmasq
dropbear
dtc
e2fsprogs
ethtool
eudev
expat
fmc
fping
gcc-runtime
glib-2.0
glib-networking
gmp
gnutls
gptfdisk
grpc
haveged
hping3
i2c-tools
iproute2
iptables
jansson
jq
json-c
jsoncpp
kexec-tools
kmod
lasso
ldns
libaio
libarchive
libcap
libdnet
libecap
libestr
libevent
libfastjson
libffi
libgcc
libgcrypt
libgpg-error
libgudev
libidn2
libmbim
libpam
libpcap
libpcre
libpsl
libqmi
libseccomp
libsodium
libsoup-2.4
libtins
libtirpc
libtool
libubox
libunistring
libusb-compat
libusb1
libxml2
libzip
licenses.txt
lighttpd
linux-meraki
logrotate
lua
lua-filesystem
lua-json
lua-penlight
lvm2
lxc
lzo
memtester
meraki-perf
modemmanager
mtd-openwrt
mtd-utils
mtr
musl
ncurses
net-snmp
netbase
nettle
nghttp2
nng
nuttcp
onig
openl2tp
openldap
openntpd
opkg-utils
pam-ldap
pam-radius
pam-script
pciutils
pimd
popt
ppp
protobuf
protobuf-c
re2
rsyslog
run-postinsts
shadow
shadow-securetty
snort
sqlite3
squid
strongswan
tcpdump
terminal-receiver
ubus
uidmapshift
usb-modeswitch
usbutils
util-linux
wireless-tools
wmi
xl2tpd
xmlsec1
xz
yajl
yaml-cpp
zlib