• Create new PDFs, add pages, draw text and vector graphics, register reusable Form XObjects, place images, and save to files or caller-owned streams.
• Load existing PDFs, inspect page boxes, search bookmark destinations, copy pages, insert pages, extract pages, reorder pages, delete pages, merge documents, stamp or watermark content, and update document information.
• Add hyperlinks, named destinations, outlines, file attachments, comments, popups, highlight annotations, free-text annotations, redaction annotations, watermark annotations, page thumbnails, layers, page transitions, and viewer preferences.
• Create AcroForm fields, generated appearance streams, signature fields, multi-line and comb text fields, rich-text field values, XFA packet containers, form-field trigger wrappers, and multiple Unicode fonts in the AcroForm resource dictionary where the selected standard profile allows them.
• Inspect, update, rename, remove, or flatten fields in loaded AcroForm documents before saving an edited copy.
• Embed and subset TrueType, Type 1 PFB, OpenType-CFF, and CID-keyed CFF fonts for compact multilingual output, including CJK-heavy documents.
• Generate Unicode text, right-to-left text, vertical text, supplementary-plane characters such as emoji, Arabic / Persian / Urdu shaping, Latin standard ligatures, Devanagari reordering, and OpenType GSUB-based glyph output with matching /CIDToGIDMap, /W, and /ToUnicode integration.
• Import JPEG, bitmap, TIFF, JPEG2000, JBIG2, WMF, and EMF content, with zlib-ng Flate compression and libjpeg-turbo backed JPEG handling.
• Protect documents with passwords, AES-128, AES-256, PDF 2.0 AES-256 R6, public-key recipient encryption, and permission flags.
• Sign PDFs with in-process PFX / PKCS#12 support and PAdES B-B, B-T, B-LT, and B-LTA workflows including RFC 3161 timestamps and DSS / VRI dictionaries.
• Create text, JSON, and HTML preflight reports, apply preflight profiles and presets, aggregate batch results, embed report evidence in PDFs, compare reports, and run focused PDF/VT validation.
• Use optional PDF backends for FastReport, QuickReport, ReportBuilder, and DevExpress ExpressPrinting when existing report layouts should emit through HotPDF.
• Process very large PDFs at high speed with the Direct File API, which opens, copies, and rewrites documents directly on disk without loading the whole file into the object model. On a 2 GB benchmark document with 1.67 million objects, AES-256 encryption takes about 14 seconds, decryption about 16 seconds, and a full rewrite about 6 seconds; reading the page count of a 1.25 GB document takes milliseconds. Classic cross-reference tables, cross-reference streams, hybrid-reference files, and incrementally updated documents all stay on the direct path.
• Encrypt and decrypt with AES-256 at hardware speed: with CPU AES-NI, AES-256-CBC reaches about 442 MB/s for encryption and 832 MB/s for decryption (about 3× and 5.7× faster than the portable software path), file-to-file EncryptFile / DecryptFile calls protect or unprotect huge documents without building the object graph, and opening a large password-protected PDF uses far less memory.

• OpenType GSUB LookupType 1-8 support, script/language feature selection, Latin standard ligatures, Arabic / Persian / Urdu shaping, Devanagari reordering, and PUA synthetic codepoint emission for font-specific glyphs.
• XFA packet container support, AcroForm /AA trigger wrappers, multiple Unicode fonts in AcroForm /DR, and generated CID-font appearance streams.
• Incremental update saving, multi-signature workflows, signature placeholders, in-process CMS SignedData generation, and long-term validation dictionaries.
• Loaded-document helpers for page-box inspection, bookmark destination lookup, AcroForm field inspection, field value updates, field renaming, field removal, and form flattening.
• Preflight profile load/save/validate/merge/diff helpers, batch aggregation, embedded report validation, XMP report embedding, focused PDF/VT validation, and conservative repair from preflight reports.
• PDF 1.3 through PDF 1.7 feature gates, selected PDF 2.0 encryption support, object streams, XRef streams, OutputIntents, transparency groups, soft masks, patterns, shadings, and prepress ExtGState controls.

program HelloHotPDF;

uses
  System.SysUtils,
  HPDFDoc;

var
  PDF: THotPDF;
begin
  PDF := THotPDF.Create(nil);
  try
    PDF.AutoLaunch := False;
    PDF.FileName := 'HelloHotPDF.pdf';
    PDF.Compression := cmFlateDecode;
    PDF.EnableFontSubsetting := True;
    PDF.BeginDoc;
    PDF.CurrentPage.SetFont('Arial', [], 18);
    PDF.CurrentPage.TextOut(50, 50, 0, 'Hello HotPDF');
    PDF.EndDoc;
  finally
    PDF.Free;
  end;
end.

• Choose HotPDF when your application creates or edits PDF documents and you want a Delphi/C++Builder source-code component rather than a separate PDF service.
• Choose PDFium Component when your primary requirement is PDF rendering, viewing, page rasterization, text extraction, and interactive viewer UI integration.
• Choose losLab PDF Library when the project is already built around the PDFlibPas API surface, or when you need DLL, ActiveX, or Dylib integration options alongside the Delphi/C++Builder source library.