Raph Levien | |
---|---|
Born | 1970 (age 51–52) |
Citizenship | American |
Alma mater | University of California, Berkeley |
Occupation | Programmer |
Employer | |
Known for | Advogato |
Children | 2 |
Website | www |
Raphael Linus Levien (also known as Raph Levien; born April 6, 1970) is a software developer, a member of the free software developer community, through his creation of the Advogato virtual community and his work with the free software branch of Ghostscript. From 2007 until 2018, and from 2021 onwards, he was employed at Google. [1] [2] [3] He holds a PhD in Computer Science from UC Berkeley. [4] He also made a computer-assisted proof system similar to Metamath: Ghilbert. In April 2016, Levien announced a text editor made as a "20% Project" (Google allows some employees to spend 20% of their working hours developing their own projects): Xi.
The primary focus of Levien's work and research is in the varied areas regarding the theory of imaging—that is, rendering pictures and fonts for electronic display, which in addition to being aesthetically and mathematically important also contribute to the accessibility and search-openness of the web.
Levien has written several papers documenting his research in halftoning technology, which has been implemented in the Gimp-Print free software package, as well as by several commercial implementations. He also created Gill, the GNOME desktop illustration application which aimed at supporting the W3C SVG standard for Vector Graphics. He states it was named after Eric Gill, the English type designer responsible for the Gill Sans, Perpetua and Joanna fonts. Direct development on Gill ceased around the year 2000, but a fork of its codebase has evolved to Sodipodi, and through it to Inkscape.
In 2009, Levien completed a PhD thesis entitled 'From Spiral to Spline: Optimal Techniques in Interactive Curve Design' [5] and published a standalone essay on the mathematical history of Elastica. [4] He calls the Elastica "A beautiful family of curves based on beautiful mathematics and a rich and fascinating history."
Beginning in 2010, his work with Google largely focused on introducing high-quality, open licensed, well organized webfonts to the internet through Google's webfont API. [6] Here, his experience with typographical technology, history and industry [5] helped to shape the development of this growing resource, though he has since moved on from the project to work on Android fonts and text layout. [1]
One of his own fonts, Inconsolata (named in 2009 as one of the ten best programming fonts by Hivelogic, [7] and generally known for its clean lines and elegant design) is now available within the Google library. [8] Regarding this font and his curves work in general, Levien had to say, "And, in fact, I don't just use the Euler spirals, I use a mixture of curves (my package is called Spiro, which is kind of an abbreviation for polynomial spirals). Most Inconsolata (the monospaced font mentioned above) is drawn using G4-continuous splines, which are a very close approximation to the Minimum Variation Curve of Henry Moreton. I now think that's overkill, and G2-continuous splines (the Euler spiral ones) are plenty, and could be done with fewer points." [1]
In November 1999, Levien founded Advogato, a social website for the free software community, to test his ideas of attack-resistant trust metrics and to provide a development-focused forum for the free software community that was free of the kind of commercial motivations of such sites as SourceForge.
The site has been successful from the point of view of the first criterion, surviving many attacks aimed at subverting the attack metric, made both by developers trying out attacks, and by spammers. The site has needed only relatively minor changes to cope with these. The site's trust metric provides, alongside Epinions, one of the two most important datasets used in the empirical analysis of trust metrics and reputation systems. Levien observed that Google's PageRank algorithm can be understood to be an attack-resistant trust metric rather similar to that behind Advogato. [9]
The site has had a more rocky road as a forum for free software developers, and currently[ when? ] hosts less discussion than at its peak as developers have moved from forums to weblogs. Due to this, Advogato has added a syndication feature that includes the weblogs of its current certified developer base. It remains one of the earlier networking sites and is still a place for active discussion on the development of free software.
Levien played a small part in precipitating the relaxation of the US crypto export legislation, by filing for a Commodities Jurisdiction Request for a T-shirt containing an implementation of the RSA encryption algorithm, in four lines of Perl. At the time (1995), the code on the T-shirt would have been regarded as a munition by the United States and other NATO governments.
ZD-Net's Interactive week summarised the issue that patents pose to the free software community: [10]
Levien recognizes the paradox: On one hand, he made money from forcing everyone who used his patented ideas to give him royalties. On the other, he shared the source code of several programs and recognized how the cooperation helped him and others. The two models were in conflict.
As a resolution to this conflict, in March 2000, Levien made a patent grant of his patent portfolio to the GPL community.
He is divorced, with two sons: Alan and Max. He is a member of the Berkeley Monthly Meeting [11] of the Religious Society of Friends (Quakers). [12] In the book TeX People: Interviews from the world of TeX , Levien notes, "I was born in Enkhuizen, the Netherlands, and moved to Virginia when I was three, so I don't really speak Dutch or anything but I do find myself with a liking for herring." [13]
A Bézier curve is a parametric curve used in computer graphics and related fields. A set of discrete "control points" defines a smooth, continuous curve by means of a formula. Usually the curve is intended to approximate a real-world shape that otherwise has no mathematical representation or whose representation is unknown or too complicated. Bézier curve is named after French engineer Pierre Bézier, who used it in the 1960s for designing curves for the bodywork of Renault cars. Other uses include the design of computer fonts and animation. Bézier curves can be combined to form a Bézier spline, or generalized to higher dimensions to form Bézier surfaces. The Bézier triangle is a special case of the latter.
TeX, stylized within the system as TeX, is a typesetting system which was designed and written by Donald Knuth and first released in 1978. TeX is a popular means of typesetting complex mathematical formulae; it has been noted as one of the most sophisticated digital typographical systems.
Metafont is a description language used to define raster fonts. It is also the name of the interpreter that executes Metafont code, generating the bitmap fonts that can be embedded into e.g. PostScript. Metafont was devised by Donald Knuth as a companion to his TeX typesetting system.
Advogato was an online community and social networking site dedicated to free software development and created by Raph Levien. In 2007, Steve Rainwater took over maintenance and new development from Raph. In 2016, Rainwater's running instance was shut down and backed up to archive.org.
Ghostscript is a suite of software based on an interpreter for Adobe Systems' PostScript and Portable Document Format (PDF) page description languages. Its main purposes are the rasterization or rendering of such page description language files, for the display or printing of document pages, and the conversion between PostScript and PDF files.
OpenType is a format for scalable computer fonts. It was built on its predecessor TrueType, retaining TrueType's basic structure and adding many intricate data structures for prescribing typographic behavior. OpenType is a registered trademark of Microsoft Corporation.
Pango is a text layout engine library which works with the HarfBuzz shaping engine for displaying multi-language text.
Inkscape is a free and open-source vector graphics editor used to create vector images, primarily in Scalable Vector Graphics (SVG) format. Other formats can be imported and exported.
Courier is a monospaced slab serif typeface. The typeface was designed by Howard "Bud" Kettler (1919–1999). Initially created for IBM's typewriters, it has been adapted for use as a computer font, and versions of it are installed on most desktop computers.
In psychology and sociology, a trust metric is a measurement or metric of the degree to which one social actor trusts another social actor. Trust metrics may be abstracted in a manner that can be implemented on computers, making them of interest for the study and engineering of virtual communities, such as Friendster and LiveJournal.
A computer font is implemented as a digital data file containing a set of graphically related glyphs. A computer font is designed and created using a font editor. A computer font specifically designed for the computer screen, and not for printing, is a screen font.
FontForge is a FOSS font editor which supports many common font formats. Developed primarily by George Williams until 2012, FontForge is free software and is distributed under a mix of the GNU General Public License Version 3 and the 3-clause BSD license. It is available for operating systems including Linux, Windows and macOS and is localized into 12 languages.
OpenID is an open standard and decentralized authentication protocol promoted by the non-profit OpenID Foundation. It allows users to be authenticated by co-operating sites using a third-party identity provider (IDP) service, eliminating the need for webmasters to provide their own ad hoc login systems, and allowing users to log in to multiple unrelated websites without having to have a separate identity and password for each. Users create accounts by selecting an OpenID identity provider, and then use those accounts to sign on to any website that accepts OpenID authentication. Several large organizations either issue or accept OpenIDs on their websites.
Cambria is a transitional serif typeface commissioned by Microsoft and distributed with Windows and Office. It was designed by Dutch typeface designer Jelle Bosma in 2004, with input from Steve Matteson and Robin Nicholas. It is intended as a serif font that is suitable for body text, that is very readable printed small or displayed on a low-resolution screen and has even spacing and proportions.
Calibri is a digital sans-serif typeface family in the humanist or modern style. It was designed by Luc(as) de Groot in 2002–2004 and released to the general public in 2007, with Microsoft Office 2007 and Windows Vista. In Office 2007, it replaced Times New Roman as the default typeface in Word and replaced Arial as the default in PowerPoint, Excel, Outlook, and WordPad. De Groot described its subtly rounded design as having "a warm and soft character".
Corbel is a humanist sans-serif typeface designed by Jeremy Tankard for Microsoft and released to consumers in 2007. It is part of the ClearType Font Collection, a suite of fonts from various designers released with Windows Vista. All start with the letter C to reflect that they were designed to work well with Microsoft's ClearType text rendering system, a text rendering engine designed to make text clearer to read on LCD monitors. The other fonts in the same group are Calibri, Cambria, Candara, Consolas and Constantia.
Bitstream Charter is a serif typeface designed by Matthew Carter in 1987 for Bitstream Inc. Charter is based on Pierre-Simon Fournier’s characters, originating from the 18th century. Classified by Bitstream as a transitional-serif typeface, it also has features of a slab-serif typeface and is often classified as such.
Ipe extensible drawing editor is a free vector graphics editor for creating figures in PDF or EPS format. It can be used for making small figures for inclusion into LaTeX documents as well as making multi-page PDF presentations. It is developed by Otfried Cheong since 1993 and initially worked on SGI workstations only. Ipe 6 was released in 2003 which changed the file format into XML code embedded into PDF and EPS files. Ipe 7 was released in 2009. Ipe 7 can be compiled under Windows, macOS and Unix but binaries are available for many distributions.
Web typography refers to the use of fonts on the World Wide Web. When HTML was first created, font faces and styles were controlled exclusively by the settings of each web browser. There was no mechanism for individual Web pages to control font display until Netscape introduced the font
element in 1995, which was then standardized in the HTML 3.2 specification. However, the font specified by the font
element had to be installed on the user's computer or a fallback font, such as a browser's default sans-serif or monospace font, would be used. The first Cascading Style Sheets specification was published in 1996 and provided the same capabilities.
An Euler spiral is a curve whose curvature changes linearly with its curve length. Euler spirals are also commonly referred to as spiros, clothoids, or Cornu spirals.
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