# Contributors and Origins

## Authors

When possible, please instead report bugs at Verilator Issues.

The primary author is Wilson Snyder <wsnyder@wsnyder.org>.

Major concepts by Krzysztof Bieganski, John Coiner, Duane Galbi, Geza Lore, Ryszard Rozak, Yutetsu Takatsukasa, Paul Wasson, and Jie Xu.

## Contributors

Many people have provided ideas and other assistance with Verilator.

Verilator is receiving significant development support from the CHIPS Alliance, and Antmicro Ltd.

Previous major corporate sponsors of Verilator, by providing significant contributions of time or funds include: Antmicro Ltd., Atmel Corporation, Compaq Corporation, Digital Equipment Corporation, Embecosm Ltd., Fractile Ltd., Hicamp Systems, Intel Corporation, Marvell Inc., Mindspeed Technologies Inc., MicroTune Inc., picoChip Designs Ltd., Sun Microsystems Inc., Nauticus Networks Inc., SiCortex Inc, Shunyao CAD, Tenstorrent USA, Inc. and Western Digital Inc.

The contributors of major functionality are: Jeremy Bennett, Krzysztof Bieganski, Byron Bradley, Lane Brooks, John Coiner, Duane Galbi, Arkadiusz Kozdra, Geza Lore, Todd Strader, Yutetsu Takatsukasa, Stefan Wallentowitz, Paul Wasson, Jie Xu, and Wilson Snyder.

Some of the people who have provided ideas, and feedback for Verilator include:

Gilberto Abram, David Addison, Joey Ah-kiow, Thomas Dybdahl Ahle, Tariq B. Ahmad, Thomas Aldrian, Omar Alkhatib, Amal Araweelo Almis, Nikana Anastasiadis, John David Anglin, Frederic Antonin, Hans Van Antwerpen, Vasu Arasanipalai, Jens Arm, Rohan Arshid, Valentin Atepalikhin, Philip Axer, Gökçe Aydos, Chris Bachhuber, Filip Badáň, Adam Bagley, Sharad Bagri, James Bailey, Robert Balas, Marco Balboni, Matthew Ballance, Ricardo Barbedo, Andrew Bardsley, Ilya Barkov, Matthew Barr, Geoff Barrett, Kaleb Barrett, Daniel Bates, Julius Baxter, Jeremy Bennett, Michael Berman, Jean Berniolles, Victor Besyakov, Narayan Bhagavatula, Moinak Bhattacharyya, Kritik Bhimani, David Biancolin, Krzysztof Bieganski, Artur Bieniek, Michael Bikovitsky, David Binderman, Piotr Binkowski, Peter Birch, Johan Björk, David Black, Tymoteusz Blazejczyk, Scott Bleiweiss, Joel Bodenmann, David van der Bokke, Daniel Bone, Guy Bonneau, Pierre-Yves Le Borgne, Krzysztof Boroński, Gregg Bouchard, Christopher Boumenot, Paul Bowen-Huggett, Nick Bowler, Byron Bradley, Bryan Brady, Maarten De Braekeleer, Liam Braun, Charlie Brej, Nick Brereton, J Briquet, Lane Brooks, John Brownlee, KC Buckenmaier, Gijs Burghoorn, Jeff Bush, Lawrence Butcher, Tony Bybell, Congcong Cai, Iru Cai, Ted Campbell, Anthony Campos, Chris Candler, Lauren Carlson, Gregory Carver, Donal Casey, Sebastien Van Cauwenberghe, Alex Chadwick, Greg Chadwick, Marcel Chang, Aliaksei Chapyzhenka, Chih-Mao Chen, Guokai Chen, Kefa Chen, Terry Chen, Yangyu Chen, Yi-Chung Chen, Yurii Cherkasov, Hennadii Chernyshchyk, Enzo Chi, Bartłomiej Chmiel, Sergey Chusov, Robert A. Clark, Ryan Clarke, Allan Cochrane, John Coiner, Luca Colagrande, Keith Colbert, Quentin Corradi, Nassim Corteggiani, Gianfranco Costamagna, February Cozzocrea, Sean Cross, George Cuan, RJ Cunningham, Michal Czyz, Joe DErrico, Jim Dai, Lukasz Dalek, Laurens van Dam, Gunter Dannoritzer, Ashutosh Das, Julian Daube, Greg Davill, Bernard Deadman, Peter Debacker, Josse Van Delm, John Demme, Mike Denio, John Deroo, Philip Derrick, Aadi Desai, John Dickol, Ruben Diez, Danny Ding, Jacko Dirks, Ivan Djordjevic, Brad Dobbie, Paul Donahue, Jonathon Donaldson, Anthony Donlon, Caleb Donovick, Larry Doolittle, Leendert van Doorn, Sebastian Dressler, Connor Driscoll, Jonathan Drolet, Jose Drowne, Justin Yao Du, Maciej Dudek, Alex Duller, Jeff Dutton, Tomas Dzetkulic, Usuario Eda, Charles Eddleston, Chandan Egbert, Joe Eiler, Ahmed El-Mahmoudy, Trevor Elbourne, Schuyler Eldridge, Ahmed Elzeftawi, Mats Engstrom, Augustin Fabre, Robert Farrell, Julien Faucher, Olivier Faure, Sergey Fedorov, Eugene Feinberg, Eugen Fekete, Fabrizio Ferrandi, Adrian Fiergolski, Udi Finkelstein, Brian Flachs, Bill Flynn, Andrea Foletto, Maxim Fonarev, Alex Forencich, Aurelien Francillon, Marco Frank, Bob Fredieu, Manuel Freiberger, Stephane Gagnon, Duane Galbi, Mostafa Gamal, Vito Gamberini, Mateusz Gancarz, Mostafa Garnal, Benjamin Gartner, Christian Gelinek, Richard E George, Peter Gerst, Glen Gibb, Michael Gielda, Barbara Gigerl, Nimrod Gileadi, Shankar Giri, Dan Gisselquist, Szymon Gizler, Petr Gladkikh, Sam Gladstone, Mariusz Glebocki, Embedded Go, Andrew Goessling, Emil Goh, Amir Gonnen, Chitlesh Goorah, Tomasz Gorochowik, Kai Gossner, Toshiki Goto, Tarik Graba, Sergi Granell, Al Grant, Nathan Graybeal, Alexander Grobman, Dominick Grochowina, Qian Gu, Karol Gugala, Xuan Guo, Prabhat Gupta, Oscar Gustafsson, Deniz Güzel, Driss Hafdi, Abdul Hameed, Neil Hamilton, Ali Hammoud, James Hanlon, Tang Haojin, Øyvind Harboe, Jannis Harder, David Harris, Junji Hashimoto, Thomas Hawkins, Mitch Hayenga, Christian Hecken, Harald Heckmann, Robin Heinemann, Robert Henry, Stephen Henry, Sebastian Hesselbarth, David Hewson, Jamey Hicks, Joel Holdsworth, Andrew Holme, Peter Holmes, Hiroki Honda, Steve Hoover, Alex Hornung, Pierre-Henri Horrein, David Horton, Peter Horvath, Jae Hossell, Kuoping Hsu, Shou-Li Hsu, Teng Huang, Steven Hugg, Alan Hunter, James Hutchinson, Tim Hutt, Ehab Ibrahim, Edgar E. Iglesias, Shahid Ikram, Jamie Iles, Ondrej Ille, Ron K. Irvine, Fuad Ismail, Vighnesh Iyer, Ben Jackson, Daniel Jacques, Shareef Jalloq, Marlon James, Krzysztof Jankowski, Moubarak Jeje, Tobias Jensen, Eyck Jentzsch, HyungKi Jeong, Iztok Jeras, Pawel Jewstafjew, Aditya Ranjan Jha, Xie Jiacheng, Alexandre Joannou, James Johnson, Christophe Joly, Justin Jones, William D. Jones, Kees Jongenburger, Abe Jordan, Larry Darryl Lee Jr., Franck Jullien, James Jung, Yoshitomo KANEDA, Mike Kagen, Arthur Kahlich, Kaalia Kahn, G-A. Kamendje, Guy-Armand Kamendje, Vasu Kandadi, Kanad Kanhere, Patricio Kaplan, Pieter Kapsenberg, Rafal Kapuscik, Ralf Karge, Per Karlsson, Dan Katz, Sol Katzman, Amirreza Kazemi, Ian Kennedy, Ami Keren, Fabian Keßler-Schulz, John Khoo, Michael Killough, Sun Kim, Jonathan Kimmitt, Olof Kindgren, Kevin Kiningham, Cameron Kirk, Dan Kirkham, Aleksander Kiryk, Sobhan Klnv, Gernot Koch, Jack Koenig, Soon Koh, Nathan Kohagen, Pawel Kojma, Steve Kolecki, Brett Koonce, Will Korteland, Andrei Kostovski, Wojciech Koszek, Varun Koyyalagunta, Arkadiusz Kozdra, Markus Krause, David Kravitz, Natan Kreimer, Adam Krolnik, Roland Kruse, Jan Kubalek, Mahesh Kumashikar, Andreas Kuster, Sergey Kvachonok, Charles Eric LaForest, Kevin Laeufer, Ed Lander, Steve Lang, Pierre Laroche, Stephane Laurent, Walter Lavino, Christian Leber, David Ledger, Alex Lee, Larry Lee, Yoda Lee, Michaël Lefebvre, Dag Lem, Igor Lesik, Brian Li, John Li, Kay Li, Zixi Li, Davide Libenzi, Matt Liberty, Nandor Licker, Eivind Liland, Ícaro Lima, Jian Nan Lin, Kevin Lin, Yu-Sheng Lin, Charlie Lind, Andrew Ling, Jens Yuechao Liu, Jiuyang Liu, Joey Liu, Paul Liu, Derek Lockhart, Jake Longo, Geza Lore, Arthur Low, Jose Loyola, Stefan Ludwig, Martin Lueker-Boden, Dan Lussier, Konstantin Lübeck, Fred Ma, Liwei Ma, Duraid Madina, Oleh Maksymenko, Alexander Mann, Affe Mao, Rémi Marche, Julien Margetts, Chick Markley, Alexis Marquet, Mark Marshall, Alfonso Martinez, Unai Martinez-Corral, Adrien Le Masle, Yves Mathieu, Vladimir Matveyenko, Patrick Maupin, Stan Mayer, Jordan McConnon, Conor McCullough, Jason McMullan, Elliot Mednick, Yuan Mei, Andy Meier, Luiza de Melo, Rodrigo A. Melo, Benjamin Menküc, Niraj Menon, Jake Merdich, David Metz, Wim Michiels, Miodrag Milanović, Darryl Miles, Kevin Millis, Andrew Miloradovsky, David Moberg, Wai Sum Mong, Peter Monsson, Anthony Moore, Sean Moore, Javier Mora, Rodrigo Batista de Moraes, Stuart Morris, Dennis Muhlestein, John Murphy, Matt Myers, Nathan Myers, Richard Myers, Alex Mykyta, Shivaram Mysore, Eric Müller, Dimitris Nalbantis, Jitesh Nayak, Peter Nelson, Yuri Nenakhov, Felix Neumärker, Bob Newgard, Cong Van Nguyen, Trung Nguyen, Rachit Nigam, Toru Niina, Paul Nitza, Yossi Nivin, Pete Nixon, Lisa Noack, Mark Nodine, Petr Nohavica, Michael Nolan, Andrew Nolte, Mateusz Nurczyński, Joseph Nwabueze, Kevin Nygaard, Thomas O’Keeffe, Kuba Ober, Krzysztof Obłonczek, Danny Oler, Andreas Olofsson, Baltazar Ortiz, Aleksander Osman, Don Owen, Tim Paine, Deepa Palaniappan, James Pallister, Vassilis Papaefstathiou, Sanggyu Park, Brad Parker, Risto Pejašinović, Seth Pellegrino, Joel Peltonen, Morten Borup Petersen, Dan Petrisko, Thanh Tung Pham, Wesley Piard, Maciej Piechotka, David Pierce, Cody Piersall, T. Platz, Michael Platzer, Dominic Plunkett, Nolan Poe, Tuomas Poikela, George Polack, David Poole, Michael Popoloski, Roman Popov, Aylon Chaim Porat, Oron Port, Rich Porter, Rick Porter, Stefan Post, Niranjan Prabhu, Damien Pretet, Harald Pretl, Bill Pringlemeir, Usha Priyadharshini, Mark Jackson Pulver, Prateek Puri, Nikolay Puzanov, Han Qi, Jiacheng Qian, Marshal Qiao, Raynard Qiao, Yujia Qiao, Jasen Qin, Frank Qiu, Nandu Raj, Kamil Rakoczy, Danilo Ramos, Drew Ranck, Chris Randall, Anton Rapp, Josh Redford, Odd Magne Reitan, Frédéric Requin, Wajahat Riaz, Dustin Richmond, Samuel Riedel, Alberto Del Rio, Eric Rippey, Narcis Rodas, Oleg Rodionov, Ludwig Rogiers, Paul Rolfe, Michail Rontionov, Arjen Roodselaar, Arthur Rosa, Tobias Rosenkranz, Yernagula Roshit, Diego Roux, Ryszard Rozak, Dan Ruelas-Petrisko, Luca Rufer, Huang Rui, Graham Rushton, Jan Egil Ruud, Denis Rystsov, Pawel Sagan, Robert Sammelson, Adrian Sampson, John Sanguinetti, Josep Sans, Dave Sargeant, Luca Sasselli, Philippe Sauter, Martin Scharrer, Parker Schless, Martin Schmidt, Jonathan Schröter, Julie Schwartz, Galen Seitz, Sam Shahrestani, Joseph Shaker, Mark Shaw, Salman Sheikh, Zhou Shen, Zhouyi Shen, Hao Shi, James Shi, Michael Shinkarovsky, Rafael Shirakawa, Jeffrey Short, S Shuba, Fan Shupei, Ethan Sifferman, Anderson Ignacio da Silva, Rodney Sinclair, Ameya Vikram Singh, Sanjay Singh, Frans Skarman, Nate Slager, Steven Slatter, Mladen Slijepcevic, Brian Small, Garrett Smith, Gus Smith, Rachel Smith, Tim Snyder, Maciej Sobkowski, Stan Sokorac, Alex Solomatnikov, Flavien Solt, Wei Song, Trefor Southwell, Martin Stadler, Art Stamness, David Stanford, Krzysztof Starecki, Baruch Sterin, John Stevenson, Pete Stevenson, Patrick Stewart, Rob Stoddard, Tood Strader, Jean-Nicolas Strauss, John Stroebel, Ray Strouble, Matt Stroud, Sven Stucki, Howard Su, Udaya Raj Subedi, Emerson Suguimoto, Gene Sullivan, Qingyao Sun, Renga Sundararajan, Kuba Sunderland-Ober, Gustav Svensk, Rupert Swarbrick, Jevin Sweval, Paul Swirhun, Krzysztof Sychla, Shinya T-Y, Yutetsu Takatsukasa, Thierry Tambe, Jesse Taube, Drew Taussig, Christopher Taylor, David Taylor, Greg Taylor, Michael Bedford Taylor, Jose Tejada, Sören Tempel, Peter Tengstrand, Wesley Terpstra, Rui Terra, Stefan Thiede, Justin Thiel, Gary Thomas, Ian Thompson, Kevin Thompson, Mike Thyer, Jerry Tianchen, Hans Tichelaar, Tudor Timi, Viktor Tomov, Steve Tong, Topa Topino, Àlex Torregrosa, Topa Tota, Michael Tresidder, Lenny Truong, David Turner, Neil Turton, Hideto Ueno, Ethan Uppal, Mike Urbach, Joel Vandergriendt, Srini Vemuri, Srinivasan Venkataramanan, Yuri Victorovich, Ivan Vnučec, Andrew Voznytsa, Bogdan Vukobratovic, Holger Waechtler, Justin Wagner, Philipp Wagner, Stefan Wallentowitz, Johannes Walter, CY Wang, Chuxuan Wang, Shawn Wang, Yilou Wang, Zhanglei Wang, Jakub Wasilewski, Paul Wasson, Greg Waters, Thomas Watts, Eugene Weber, John Wehle, Tianrui Wei, Yin Weijie, David Welch, Thomas J Whatson, Martin Whitaker, Marco Widmer, Leon Wildman, Daniel S. Wilkerson, Daniel Wilkerson, Gerald Williams, Trevor Williams, Don Williamson, Jan Van Winkel, Jeff Winston, Max Wipfli, Joshua Wise, Clifford Wolf, Johan Wouters, Paul Wright, Tobias Wölfel, Domenic Wüthrich, Junyi Xi, Ding Xiaoliang, Liu Xiaoyi, Jie Xu, Jinyan Xu, Mandy Xu, Pengcheng Xu, Shanshan Xu, Yan Xu, Yinan Xu, Felix Yan, Zhen Yan, Jiaxun Yang, Luke Yang, Su Yang, Amir Yazdanbakhsh, Law Heng Yi, Ibrahim Burak Yorulmaz, Chentai (Seven) Yuan, Florian Zaruba, Igor Zaworski, Mat Zeno, Keyi Zhang, Xi Zhang, Alex Zhou, Huanghuang Zhou, Yike Zhou, Jiamin Zhu, Ryan Ziegler, Lan Zongwei.

Thanks to them, and all those we’ve missed mentioning above, and to those whom have wished to remain anonymous.

## Historical Origins

Verilator was conceived in 1994 by Paul Wasson at the Core Logic Group at Digital Equipment Corporation. The Verilog code that was converted to C was then merged with a C-based CPU model of the Alpha processor and simulated in a C-based environment called CCLI.

In 1995 Verilator started being used for Multimedia and Network Processor development inside Digital. Duane Galbi took over the active development of Verilator, and added several performance enhancements, and CCLI was still being used as the shell.

In 1998, through the efforts of existing DECies, mainly Duane Galbi, Digital graciously agreed to release the source code. (Subject to the code not being resold, which is compatible with the GNU Public License.)

In 2001, Wilson Snyder took the kit, added a SystemC mode, and called it Verilator2. This was the first packaged public release.

In 2002, Wilson Snyder created Verilator 3.000 by rewriting Verilator from scratch in C++. This added many optimizations, yielding about a 2-5x performance gain.

In 2009, major SystemVerilog and DPI language support was added.

In 2018, Verilator 4.000 was released with multithreaded support.

In 2019, Verilator joined the CHIPS Alliance.

In 2022, Verilator 5.000 was released with IEEE scheduling semantics, fork/join, delay handling, DFG performance optimizations, and other improvements.

Currently, various language features and performance enhancements are added as the need arises, focusing on completing Universal Verification Methodology (UVM, IEEE 1800.2-2017) support.