Pros of Zathura

• Lightweight and minimalist design, focusing on keyboard-driven navigation
• Extensive plugin system allowing for customization and support for various document formats
• Integrated with Vim-like keybindings, appealing to power users

Cons of Zathura

• Less feature-rich compared to Sioyek, especially in terms of advanced PDF navigation
• Limited built-in support for academic reading features like reference management
• Steeper learning curve for users not familiar with Vim-like interfaces

Code Comparison

Zathura configuration (zathurarc):

set selection-clipboard clipboard
set window-title-basename true
map <C-i> zoom in
map <C-o> zoom out

Sioyek configuration (prefs_user.config):

custom_background_color 0.18 0.20 0.25
custom_text_color 0.90 0.90 0.90
startup_commands toggle_custom_color
super_fast_search 1

Both applications allow for extensive customization through configuration files, but Sioyek's configuration tends to focus more on academic-specific features and visual customization, while Zathura's configuration often emphasizes keybindings and general behavior.

Pros of Calibre

• Comprehensive e-book management system with library organization, metadata editing, and format conversion
• Cross-platform support (Windows, macOS, Linux) with a user-friendly GUI
• Large and active community with extensive plugin ecosystem

Cons of Calibre

• Larger resource footprint and slower startup times
• More complex interface with a steeper learning curve
• Not specifically optimized for academic or research-oriented PDF reading

Code Comparison

Sioyek (C++):

void MainWindow::goto_definition() {
    std::wstring selected_text = get_selected_text();
    if (selected_text.size() > 0) {
        goto_definition(selected_text);
    }
}

Calibre (Python):

def create_book_copy(self, book_id, fmt):
    db = self.current_db.new_api
    with db.safe_read_lock:
        mi = db.get_metadata(book_id)
        path = db.format_abspath(book_id, fmt)
    return mi, path

Both projects use different programming languages and have distinct focuses. Sioyek emphasizes efficient PDF navigation and academic reading, while Calibre offers comprehensive e-book management features. The code snippets reflect their respective specializations, with Sioyek handling text selection and definition lookup, and Calibre managing book metadata and file paths.

Pros of KOReader

• Supports a wider range of e-reader devices, including Kindle, Kobo, and PocketBook
• More extensive customization options for reading experience
• Includes a built-in dictionary and translation features

Cons of KOReader

• Less optimized for academic PDF reading and annotation
• May have a steeper learning curve for new users
• Limited support for advanced PDF features like hyperlinks and forms

Code Comparison

KOReader (Lua):

local ReaderUI = require("apps/reader/readeruiMenu")
local ReaderView = require("ui/widget/readerview")

function ReaderUI:init()
    self.view = ReaderView:new()
    -- Additional initialization code
end

Sioyek (C++):

class PDFViewerApplication {
public:
    PDFViewerApplication();
    void initialize();
    void loadDocument(const QString& filePath);
    // Additional methods
};

While both projects aim to provide e-reading capabilities, KOReader focuses on a broader range of devices and formats, while Sioyek specializes in academic PDF reading with advanced features. KOReader uses Lua for its codebase, allowing for easier customization, while Sioyek is built with C++, potentially offering better performance for complex PDF rendering and manipulation.

Pros of qpdf

• Comprehensive PDF manipulation tool with a wide range of features
• Command-line interface for easy integration into scripts and workflows
• Actively maintained with regular updates and bug fixes

Cons of qpdf

• Lacks a graphical user interface, which may be less user-friendly for some
• Primarily focused on PDF manipulation rather than viewing or annotation
• Steeper learning curve for users unfamiliar with command-line tools

Code Comparison

qpdf:

QPDF::QPDFWriter w(pdf);
w.setOutputFilename(outfilename);
w.write();

sioyek:

void PDFViewerApplication::openFile(const QString& filePath)
{
    m_document = Poppler::Document::load(filePath);
    // ... (additional code to render and display the PDF)
}

Summary

qpdf is a powerful command-line tool for PDF manipulation, offering extensive features for advanced users and developers. sioyek, on the other hand, is a PDF viewer with a focus on research and technical documents, providing a user-friendly interface with features like synctex support and vim-like keybindings. While qpdf excels in PDF processing tasks, sioyek is better suited for reading and annotating PDFs, especially for academic or technical purposes.

Pros of SumatraPDF

• More mature and established project with a larger user base
• Supports a wider range of file formats (PDF, EPUB, MOBI, CBZ, CBR, etc.)
• Faster rendering and lower memory usage for large documents

Cons of SumatraPDF

• Less focus on academic/research features compared to Sioyek
• User interface may feel less modern and customizable
• Fewer advanced PDF navigation and annotation features

Code Comparison

SumatraPDF (C++):

void WindowInfo::ShowNotification(const WCHAR* message, bool autoDismiss, bool highlight) {
    NotificationWnd* wnd = new NotificationWnd(this->hwndFrame, message, autoDismiss, highlight);
    wnd->Create();
}

Sioyek (C++):

void MainWidget::show_notification(QString message, int time_to_show) {
    notification_widget->set_text(message);
    notification_widget->show();
    QTimer::singleShot(time_to_show, notification_widget, &NotificationWidget::hide);
}

Both projects use C++ for their core functionality, but Sioyek incorporates Qt for its user interface, while SumatraPDF uses native Windows APIs. Sioyek's code tends to be more modern and object-oriented, while SumatraPDF's codebase is older and more procedural in style.

Pros of pdf.js

• Web-based and cross-platform compatible
• Widely adopted and integrated into many browsers
• Extensive documentation and community support

Cons of pdf.js

• Slower performance for large or complex PDFs
• Limited advanced features compared to native PDF readers
• Requires JavaScript to be enabled in the browser

Code Comparison

pdf.js:

PDFJS.getDocument(url).then(function(pdf) {
  pdf.getPage(1).then(function(page) {
    var scale = 1.5;
    var viewport = page.getViewport(scale);
    // Render page
  });
});

Sioyek:

void PDFViewerApplication::openDocument(const QString& filePath) {
    m_document = std::make_unique<PDFDocument>(filePath);
    m_currentPage = 1;
    renderCurrentPage();
}

Key Differences

• pdf.js is written in JavaScript for web browsers, while Sioyek is a native application written in C++
• Sioyek focuses on academic and research-oriented features, whereas pdf.js aims for general-purpose PDF viewing
• pdf.js has a larger user base and more frequent updates, while Sioyek offers a more specialized feature set

Use Cases

• pdf.js: Web applications, online document viewers, and browser extensions
• Sioyek: Academic research, technical document reading, and specialized PDF workflows