Editing L4 microkernel family (section)

== Other research and development ==
Osker, an OS written in [[Haskell]], targeted the L4 specification; although this project focused mainly on the use of a [[functional programming]] language for OS development, not on microkernel research.<ref>
{{cite journal
 |last1 = Hallgren |first1 = T.
 |last2 = Jones |first2 = M.P.
 |last3 = Leslie |first3 = R.
 |last4 = Tolmach |first4 = A.
 |journal = ACM SIGPLAN Notices
 |year = 2005
 |title = A principled approach to operating system construction in Haskell
 |url = http://web.cecs.pdx.edu/~apt/icfp05.pdf
 |volume = 40
 |issue = 9
 |pages = 116–128
 |issn = 0362-1340
 |doi = 10.1145/1090189.1086380
 |access-date = 2010-06-24
 |url-status = live
 |archive-url = https://web.archive.org/web/20100615164444/http://web.cecs.pdx.edu/~apt/icfp05.pdf
 |archive-date = 2010-06-15
}}</ref>

RedoxOS<ref>{{cite web |url=https://www.redox-os.org/ |title=RedoxOS |website=[[RedoxOS]]}}</ref> is a Rust based operating system, that is also inspired by seL4, and uses a micro kernel design.

CodeZero<ref>{{cite web |url=https://os.inf.tu-dresden.de/pipermail/l4-hackers/2009/004166.html |title=Announce: Introducing Codezero |website=[[Dresden University of Technology]]}}</ref> is an L4 microkernel for embedded systems with a focus on virtualization and implementation of native OS services. There is a [[GPL 3|GPL]]-licensed version,<ref>{{cite web |url=https://github.com/jserv/codezero |title=jserv/codezero: Codezero Microkernel |website=[[GitHub]] |access-date=2020-10-20 |url-status=live |archive-url=https://web.archive.org/web/20150815113256/https://github.com/jserv/codezero |archive-date=2015-08-15}}</ref> and a version that was relicensed by B Labs Ltd., acquired by [[Nvidia]], as closed source and forked in 2010.<ref>{{cite web |url=http://l4dev.org/ |title=Code Zero : Embedded Hypervisor and OS |access-date=25 January 2016 |url-status=dead |archive-url=https://web.archive.org/web/20160111122321/http://l4dev.org/ |archive-date=11 January 2016}}</ref><!-- clarify OKL4 and Iggy license |date=February 2015 --><ref>{{cite web |url=http://dev.b-labs.com/ |title=B Labs &#124; Mobile Virtualization solutions, Android and Linux virtualization for the ARM architecture |access-date=2 February 2014 |url-status=dead |archive-url=https://web.archive.org/web/20140202174213/http://dev.b-labs.com/ |archive-date=2 February 2014}}</ref>

F9 microkernel,<ref>{{cite web |url=https://github.com/f9micro |title=F9 Microkernel |website=[[GitHub]] |access-date=2020-10-20}}</ref> a BSD-licensed L4 implementation, is dedicated to [[ARM Cortex-M]] processors for deeply embedded devices with memory protection.

The NOVA OS Virtualization Architecture<ref>{{cite web |url=https://hypervisor.org/ |title=NOVA Microhypervisor website |access-date=2021-01-09}}</ref> is a research project with focus on constructing a secure and efficient virtualization environment<ref name="Steinberg_Kauer_EuroSys_2010">
{{cite conference
 |last1=Steinberg |first1=Udo
 |last2=Kauer |first2=Bernhard
 |title = NOVA: A Microhypervisor-Based Secure Virtualization Architecture
 |book-title = EuroSys '10: Proceedings of the 5th European Conference on Computer Systems
 |date=April 2010
 |location = [[Paris, France]]
}}</ref><ref name="Steinberg_Kauer_IIDS_2010">
{{cite conference
 |last1=Steinberg |first1=Udo
 |last2=Kauer |first2=Bernhard
 |title=Towards a Scalable Multiprocessor User-level Environment
 |book-title = IIDS'10: Workshop on Isolation and Integration for Dependable Systems
 |date=April 2010
 |location=[[Paris, France]]
}}</ref>
with a small trusted computing base. NOVA consists of a microhypervisor, a user level [[hypervisor]] ([[virtual machine]] monitor), and an unprivileged componentised multi-server user environment running on it named NUL. NOVA runs on ARMv8-A and x86-based multi-core systems.

WrmOS<ref>{{cite web |url=https://wrmlab.org/projects/wrmos |title= WrmOS |access-date=2020-10-20}}</ref> is a [[real-time operating system]] based on L4 microkernel. It has own implementations of kernel, standard libraries, and network stack, supporting ARM, SPARC, x86, and x86-64 architectures. There is the paravirtualized Linux kernel (w4linux<ref>{{cite web |url=https://wrmlab.org/projects/w4linux |title=w4linux is paravirtualized Linux kernel working on WrmOS |access-date=2020-10-20}}</ref>) working on WrmOS.

Helios is a microkernel inspired by seL4.<ref>{{Cite web |title=~sircmpwn/helios – An experimental microkernel – sourcehut git |url=https://git.sr.ht/~sircmpwn/helios |access-date=2023-02-20 |website=git.sr.ht}}</ref> It is part of the Ares operating system, supports x86-64 and aarch64 and is still under active development as of February 2023.<ref>{{Cite web |title=Helios |url=https://ares-os.org/docs/helios/ |access-date=2023-02-20 |website=ares-os.org |language=en-us}}</ref>