Users who have come to understand and appreciate the advantages of a typesetting program like LaTeX [1] prefer to use it exclusively when drafting text. These same users also want it to be available for everyday use on all of their devices. In fact, various possibilities do exist for installing the program on tablets and the like. However, the installation process comes with numerous problems. Consequently, even experienced users are not always able to complete installation successfully without apps like TeX Writer [2] or VerbTeX [3] already running on the target platform.

Therefore, the idea of using LaTeX in an online browser is appealing, because it is a simple and elegant solution that gets around the problems encountered when installing other applications. Additionally, online access makes it possible to work in groups and take advantage of versioning. In this article, I examine three candidates – Papeeria [4], ShareLaTeX [5], and Overleaf [6] – to see whether online services offer faultless capabilities or whether users are forced to accept restrictions so painful that they forego using the services altogether.

Building, distributing, and maintaining this type of online service is a complicated endeavor. Not everybody is up to the task, as is evident from the failures experienced by such services as Fidus Writer [7], FlyLaTeX [8], SpanDeX [9], LaTeX Lab [10], and MonkeyTeX.

How They Work

The approaches taken by the online services tested here share striking similarities:

• They install one or more releases of TeX Live [11] as the standard LaTeX on a Linux server.
• The files to be edited land in the user's document directory on the server, and the service automatically saves them there regularly.
• Users edit the files remotely in their browser via an online editor; meanwhile, the editor allows multiple users to share a file.
• An online PDF viewer displays the LaTeX document that has been compiled on the server. The compiling process is the same as the one LaTeX uses on a local installation.

This seemingly simple concept can only be implemented with the involvement of a wide range of technologies. The online editors are mostly implemented as asynchronous JavaScript applications.

The Competition

The test data came from two existing LaTeX projects that were uploaded and compiled online, with the results checked thoroughly. In this article, I looked at a project shared between coworkers, as well as a project in which work was performed simultaneously by multiple users on the same file.

Those who want to create new projects will find that the services typically offer a plethora of templates. For the most part, they are applicable to dissertations and articles for scientific journals. The number of file templates should not be the criterion you use to decide for or against a particular service, though. Because all LaTeX services behave like a local installation, it suffices to put any random template in the document directory. LaTeX finds the file and integrates it. The same goes for LaTeX packages that you want to load during compilation. If they are not preinstalled, you only need to get them via the Internet and move them to the document directory.

LaTeX can handle any number of text types in addition to scientific text, including everything from Advent calendars to greeting cards. However, the people interested in these types of documents are probably not interested in the online services I talk about in this article. One as yet unresolved issue is that none of the templates come with information on the LaTeX compile settings. This goes for all of the services described here. Presumably, most users compile with pdflatex, whereas a few turn to XeLaTeX to get working PDF files.

Additionally, all three services offer free access to a more restricted version than the fee-based choice in terms of time period for use or the number of available functions.

Papeeria

Although Papeeria [4] was created by a Russian company, the LaTeX user is barely aware of it because most of the pages are in English. When using free testing access to the program, it is important to remember that the platform makes all saved documents publicly accessible after the first project. A fee-based account costs $5 dollars per month.

To begin, you upload an existing LaTeX project as a ZIP archive, and the service decompresses and puts the files in your document directory. The standard setting uses TeX Live 2015. If problems occur, you can turn to a 2013 version to compile.

The developers have not corrected all of the installation errors. During testing, I found that installation of the EB Garamond font was faulty. Once notified, Papeeria responded promptly via email that three full-time programmers had received an SMS alert. However, I was still able to reproduce the bug two months later; thus, it would seem that bug reports are ignored in spite of intensive communication efforts.

Figure 1 shows the very straightforward interface. Those familiar with LaTeX will be able to navigate easily. The four frames display the project files, LaTeX code, PDF presentation, and error messages and warnings.

Figure 1: The LaTeX online platform Papeeria divides the work area into four frames and offers TeX Live 2013 and 2015.