We're a bootstrapped company building open source solutions for spreadsheets and structured data. With over 1.8M unique monthly visitors, companies across the business world turn to us for challenging data processing problems. Over the last 10 years, we have pushed the boundaries of JavaScript and the web.

In this role, you will master new and established technologies while working on high-impact projects used by millions of people across the world. Balancing research and engineering, you will design and implement creative solutions that draw from your academic and professional experience.

https://sheetjs.com/careers/ more details

At the time, there was no "Safety Report" to indicate why Bing thought it was dangerous. The report page linked to https://www.bing.com/toolbox/bing-site-safety?url=https%3a%2... and it said "That web page doesn't exist"

To fix it, we had to register with "Bing Webmaster Tools" (https://www.bing.com/webmasters/about) and raise a support ticket.

Within a few days, the issue "resolved itself". It's possible that raising a ticket forced some automatic refresh of the indexed data for the domain.

We're a bootstrapped company building open source solutions for spreadsheets and structured data. With over 1.5M unique monthly visitors, companies across the business world turn to us for challenging data processing problems. Over the last 10 years, we have pushed the boundaries of JavaScript and the web.

In this role, you will master new and established technologies while working on high-impact projects used by millions of people across the world. Balancing research and engineering, you will design and implement creative solutions that draw from your academic and professional experience.

https://sheetjs.com/careers/ more details

[1] https://github.com/facebookresearch/shumai

In the same way that Python developers are interested in extending their ecosystem to other spaces, JavaScript developers are interested in growing into the data science space. But that doesn't happen unless there's a clear benefit for switching.

What advantages do a native JS solution have over Python? Performance: There are arguably many more developers and companies focused on pure JS performance than python. Community: A JS solution opens up a much larger pool of talent to build innovative solutions. Cost: Running heavy computations client-side, in the web browser, reduces costs for service providers.

PS: We're hiring for this and other related problems https://sheetjs.com/careers

We (https://sheetjs.com/) have been looking into document compatibility for 10 years (celebrating our 10 year birthday this week!), and our eponymous open source project https://github.com/sheetjs/sheetjs is used by companies large and small. It's not a particularly glamorous subject and doesn't tend to electrify people in the same way as build tools or frameworks.

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There are ways to improve upon the space, but the problem is that the world has changed. Excel was designed to be the "center of the universe", a creative substrate that bypassed org security policies and enabled extremely flexible line of business tools. Excel was designed to be used by one user at a time, with fundamental inconsistencies blocked at the UI level (for example, try entering a bad custom number format). This made sense 20 years ago, but it doesn't make as much sense now.

The current crop of SaaS companies effectively monetize access to the data. They aren't incentivized to make it easy to export metadata back to Excel -- they want to keep you using the software. This runs at odds with the data portability and freedom that is needed for a successful replacement.

Whatever will replace Excel won't be a facsimile of the current tooling (what Google and Apple are trying to do), nor will it be a siloed experience (what the myriad of SaaS apps are trying to do).

"Â ", where the second character is a unicode non-breaking space characters (U+00A0), is the CP1252 encoding of the byte sequence [0xC2, 0xA0] which is the UTF-8 encoding of "\u00A0". So all that really needs to happen is to get Excel to think that the file is UTF-8 encoded.

The fix? For XLS, there is a special Codepage record that indicates how strings are to be interpreted. The magic value to force UTF-8 interpretation is 65001, and it is possible to use a hex editor to find exactly where that record is located and change it.

> Inside Microsoft – A ‘Velvet Sweatshop’ or a High-Tech Heaven?

https://www.seattletimes.com/business/archive-inside-microso...

> Caution: Password to modify is not a security feature. ... Malicious users can edit the file and remove the password.

This type of "protection" is also present in the VBA blobs (where you can change a few bytes and work around the VBA protection)

Saving a file with a password to open actually employs encryption. The exact setting can be tuned with registry settings, but is typically AES-128-CBC.

Saving a file as "read-only" encrypts the file with the standard password "VelvetSweatshop"

It is certainly an interesting format, and Excel completely mangles the data (whether it was intentional is up for debate). For example, the value

    1,0
    "0.3"

    1,0
    "=""0.3"""

 [1] https://atariwiki.org/wiki/attach/VisiCalc/DIF_Technical_Specification.pdf

tl;dr: the project involves "crowdsourced research" which benefits from popularity.

The main social goal with the project is data preservation and integrity. Large-scale economic and political decisions are made from data and analyses in spreadsheets. For example, last year in the UK, COVID cases were underreported thanks to Excel minutiae https://www.bbc.com/news/technology-54423988

Due to various corporate stratagems, the older data representations were intentionally obfuscated. To support Excel, many developers poked around at Excel files and guessed at the structures.

In this environment, the biggest challenge is finding worksheets with random corner cases. These types of files are not easy to create and fuzzing has limited effectiveness. This is where open source and popularity come into play. The open source and JS nature of the project helps reduce testing friction (https://oss.sheetjs.com/ runs in the web browser, no need to install anything) and encourage bug reports with test cases.

There will always be "entitled users" and "low quality bug reports" but that comes with the territory. There are also meaningful issues and code contributions. Efforts at trying to prevent the low quality contributions also discourage higher quality contributions.

Under the Apple "Mac-Roman" encoding [1], the standard MacOS encoding before OSX switched to Unicode, byte 0xBD currently is capital omega (U+03A9 Ω). However, in the original 1994 release of the character set, they erroneously mapped to the ohm sign (U+2126 Ω) Apple eventually fixed this in 1997, as noted in the changelog:

    #       n04  1997-Dec-01    Update to match internal utom, ufrm:
    #                           Change standard mapping for 0xBD from U+2126
    #                           to its canonical decomposition, U+03A9.

This discrepancy leads to a huge number of strange issues with various versions of Excel for Mac (BOM-less CSV, SYLK and other plaintext formats default to system encoding) and other software that use Microsoft's interpretation of Apple's Mac-Roman encoding rather than Apple's official character set mapping.

[1] http://www.unicode.org/Public/MAPPINGS/VENDORS/APPLE/ROMAN.T...

[2] http://www.unicode.org/Public/MAPPINGS/VENDORS/MICSFT/MAC/RO...

Back in 2015, 'patio11 reached out to us. In addition to a structured license purchase, he gave great insights and actually wrote a blog post about the experience https://www.kalzumeus.com/2015/01/28/design-and-implementati...

Today, we offer paid software builds to solve related problems and it allows us to work on SheetJS full-time!

Excel has to contend with nearly 40 years of backwards compatibility (MultiPlan, the predecessor to Excel, was released in 1982) and a deep userbase that literally has decades of experience and muscle memory with the software. The Symbolic Link "SYLK" file format introduced in MultiPlan is still supported in recent versions of Excel, leading to the infamous CSV "ID" issue.

Many of our users still run very old versions of Excel and Windows (e.g. Excel 5.0 on Windows 95) because a change in a future version of Excel caused problems or gave different results.

If you are trying to generate a file that plays nice with Excel, there is a way to force a specific delimiter with the "sep" pragma:

    sep=|
    a|b|c
    1|2|3

In the python space, there are libraries like openpyxl and xlrd, but the real hurdle is introducing python into an ecosystem which otherwise has no natural knowledge. JavaScript is the language of choice for modern Excel addins as Excel provides an actual API for it https://docs.microsoft.com/en-us/office/dev/add-ins/referenc...