diff --git a/ChangeLog b/ChangeLog
index 7fa45b45..ffa44e79 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -21,7 +21,7 @@
     be wildcard expansions when used with DNSSEC proofs.  Only direct
     queries for those types are allowed to be wildcard expansions.
   * Bugfix PR#379: Miscelleneous double free or corruption, and corrupted
-    memory double linked list detected issue, whith serving functionality.
+    memory double linked list detected issue, with serving functionality.
     Thanks maddie and Bruno Pagani
   * Security Bugfix PR#293: Check sha256 pinset's
     with OpenSSL native DANE functions for OpenSSL >= 1.1.0
@@ -238,7 +238,7 @@
     Allow misshing "address_type" in address dicts.
   * TLS session resumption
   * -C <config file> option to getdns_query to configure context 
-    from a json like formated file.  The output of -i (print API
+    from a json like formatted file.  The output of -i (print API
     information) can be used as config file directly.
     Settings may also be given in this format as arguments of
     the getdns_query command directly.
@@ -387,7 +387,7 @@
 * 2015-09-04: Version 0.3.2
   * Fix returned upstreams list by getdns_context_get_api_information()
   * Fix some autoconf issues when srcdir != builddir
-  * Fix remove build date from manpage version for reproducable builds
+  * Fix remove build date from manpage version for reproducible builds
   * Fix transport fallback issues plus transport fallback unit test script
   * Fix string bindata's need not contain trailing zero byte
   * --enable-stub-only configure option for stub only operation.
@@ -540,7 +540,7 @@
   * Build from separate build directory
   * Anticipate libunbound not returning the answer packet
   * Pretty print bindata's representing IP addresses
-  * Anticipate absense of implicit DSO linking
+  * Anticipate absence of implicit DSO linking
   * Mention getdns specific options to configure in INSTALL
     Thanks Paul Hoffman
   * Mac OSX package built instructions for generic user in README.md
diff --git a/configure.ac b/configure.ac
index 1bba9a5f..5a83c489 100644
--- a/configure.ac
+++ b/configure.ac
@@ -49,7 +49,7 @@ AC_ARG_WITH([piddir],
   [with_piddir=${default_piddir}])
 AC_SUBST([runstatedir], [$with_piddir])
 
-# Dont forget to put a dash in front of the release candidate!!!
+# Don't forget to put a dash in front of the release candidate!!!
 # That is how it is done with semantic versioning!
 #
 AC_SUBST(RELEASE_CANDIDATE, [rc1])
@@ -1471,7 +1471,7 @@ AH_BOTTOM([
 
 #ifdef GETDNS_ON_WINDOWS
  /* On windows it is allowed to increase the FD_SETSIZE
-  * (and nescessary to make our custom eventloop work)
+  * (and necessary to make our custom eventloop work)
   * See: https://support.microsoft.com/en-us/kb/111855
   */
 # ifndef FD_SETSIZE
diff --git a/project-doc/cachedesign.txt b/project-doc/cachedesign.txt
index 71606e7c..da5a839f 100644
--- a/project-doc/cachedesign.txt
+++ b/project-doc/cachedesign.txt
@@ -53,9 +53,9 @@ Local configuration via API or local file (e.g. /etc/getdns.conf, ~/.getdnsrc)
     - max TTL/TTL override (separate for pos/neg cache entries)
     - inclusions (use cache for specified domains) (maybe over-eng)
     - exceptions (avoid ache for specified domains) (maybe over-eng)
-    - persistant vs. transitory cache
+    - persistent vs. transitory cache
 
-- cache data store via Berkely db to allow for persistance
+- cache data store via Berkely db to allow for persistence
 
 - negative cache TTL derived from SOA
 
diff --git a/src/dnssec.c b/src/dnssec.c
index 3bf92d58..5a0062dd 100644
--- a/src/dnssec.c
+++ b/src/dnssec.c
@@ -79,8 +79,8 @@
 /* Outline of operations in this file
  * ==================================
  *
- * Data structure to represent the delegation/referal hierarchy
- * ------------------------------------------------------------
+ * Data structure to represent the delegation/referral hierarchy
+ * -------------------------------------------------------------
  * Both the "dnssec_return_validation_chain" extension, and the 
  * getdns_validate_dnssec() function use the same structs to represent the 
  * involved pieces of the DNS in a hierarchical manner.
@@ -134,7 +134,7 @@
  * in a _getdns_rrset, and the rrsig_iter to iterate over the RRSIGs covering
  * the RRs in the _getdns_rrset.
  *
- * The _getdns_rrsets are already equiped with name/rr_class and rr_type when
+ * The _getdns_rrsets are already equipped with name/rr_class and rr_type when
  * constructing the linked list of chain_nodes up to the root for a chain_head.
  * They are substantiated with the wireformat packets that are returned with 
  * the queries that were sheduled in the context of the 
@@ -146,7 +146,7 @@
  * of non-existance.
  *
  * The getdns_validate_dnssec() function, after it constructed the chain_heads
- * hierarchy, creates an artifical packet for the support records and equips
+ * hierarchy, creates an artificial packet for the support records and equips
  * all the ds and dnskey _getdns_rrsets on the chain_nodes with this packet.
  *
  * The _getdns_rrset + support function and data types are defined in section:
diff --git a/src/getdns/getdns.h.in b/src/getdns/getdns.h.in
index 788f0d94..23e59cf4 100644
--- a/src/getdns/getdns.h.in
+++ b/src/getdns/getdns.h.in
@@ -1392,7 +1392,7 @@ char *getdns_display_ip_address(const getdns_bindata
  * @param value The callback function that will be called when any context is
  *              changed. A update callback function can be deregistered by
  *              passing NULL.
- * @return GETDNS_RETURN_GOOD when succesful.
+ * @return GETDNS_RETURN_GOOD when successful.
  * @return GETDNS_RETURN_INVALID_PARAMETER when context was NULL.
  */
 getdns_return_t
diff --git a/src/getdns/getdns_extra.h.in b/src/getdns/getdns_extra.h.in
index 4837771c..0859b6b0 100644
--- a/src/getdns/getdns_extra.h.in
+++ b/src/getdns/getdns_extra.h.in
@@ -829,10 +829,10 @@ getdns_context_get_dns_transport_list(getdns_context *context,
     size_t* transport_count, getdns_transport_list_t **transports);
 
 /**
- * Get the current limit for oustanding queries setting from this context.
+ * Get the current limit for outstanding queries setting from this context.
  * @see getdns_context_set_limit_outstanding_queries
  * @param[in]  context The context from which to get the setting
- * @param[out] limit The current limit for oustanding queries
+ * @param[out] limit The current limit for outstanding queries
  * @return GETDNS_RETURN_GOOD when successful
  * @return GETDNS_RETURN_INVALID_PARAMETER when context or limit was NULL.
  */
@@ -1055,7 +1055,7 @@ getdns_return_t
 getdns_context_get_tls_query_padding_blocksize(getdns_context *context, uint16_t* value);
 
 /**
- * Get whether the upstream needs to be authenticated whith DNS over TLS.
+ * Get whether the upstream needs to be authenticated with DNS over TLS.
  * @see getdns_context_set_tls_authentication
  * @see authvaulesandtext
  * @param[in]  context The context from which to get the setting
@@ -1359,7 +1359,7 @@ uint32_t getdns_get_api_version_number(void);
 
 /**
  * Returns a text describing the getdns error code, or NULL when the error
- * code is unkown.
+ * code is unknown.
  * @param err The error code for which to return the describing text
  * @return The describing text for the error code.  The string is in library
  * space and the caller must *not* free this.
@@ -1716,7 +1716,7 @@ getdns_rr_dict2wire_buf(
  *                 the buffer and point right after the just written RR.
  * @param  wire_sz On input the size of the wire buffer,
  *                 On output the amount of wireformat needed for the
- *                 wireformat will have been substracted from wire_sz.
+ *                 wireformat will have been subtracted from wire_sz.
  * @return GETDNS_RETURN_GOOD on success or an error code on failure.
  * GETDNS_RETURN_NEED_MORE_SPACE will be returned when the buffer was too
  * small.  The function will pretend that it had written beyond the end
@@ -1808,7 +1808,7 @@ getdns_rr_dict2str_buf(
  *                 the buffer and point right after the just written RR.
  * @param  str_len On input the size of the str buffer,
  *                 On output the number of characters needed for the
- *                 string will have been substracted from strlen.
+ *                 string will have been subtracted from strlen.
  * @return GETDNS_RETURN_GOOD on success or an error code on failure.
  * GETDNS_RETURN_NEED_MORE_SPACE will be returned when the buffer was too
  * small.  The function will pretend that it had written beyond the end
@@ -1887,7 +1887,7 @@ getdns_msg_dict2wire_buf(
  *                  the buffer and point right after the just written RR.
  * @param  wire_sz  On input the size of the wire buffer,
  *                  On output the amount of wireformat needed for the
- *                  wireformat will have been substracted from wire_sz.
+ *                  wireformat will have been subtracted from wire_sz.
  * @return GETDNS_RETURN_GOOD on success or an error code on failure.
  * GETDNS_RETURN_NEED_MORE_SPACE will be returned when the buffer was too
  * small.  The function will pretend that it had written beyond the end
@@ -1979,7 +1979,7 @@ getdns_msg_dict2str_buf(
  *                  the buffer and point right after the just written RR.
  * @param  str_len  On input the size of the str buffer,
  *                  On output the number of characters needed for the
- *                  string will have been substracted from strlen.
+ *                  string will have been subtracted from strlen.
  * @return GETDNS_RETURN_GOOD on success or an error code on failure.
  * GETDNS_RETURN_NEED_MORE_SPACE will be returned when the buffer was too
  * small.  The function will pretend that it had written beyond the end
@@ -2131,7 +2131,7 @@ typedef void (*getdns_request_handler_t)(
  * On failure, the current set of listening addresses is left in place.
  * Also, if there is overlap in listening_addresses between the active set
  * and the newly given set, the ones in the active set will remain in their
- * current condition and will not be closed and reopened, also all assoicated
+ * current condition and will not be closed and reopened, also all associated
  * DNS transactions will remain.
  */
 getdns_return_t
diff --git a/src/gldns/parseutil.h b/src/gldns/parseutil.h
index 1546e8be..a044c4de 100644
--- a/src/gldns/parseutil.h
+++ b/src/gldns/parseutil.h
@@ -58,7 +58,7 @@ time_t gldns_mktime_from_utc(const struct tm *tm);
  * The function interprets time as the number of seconds since epoch
  * with respect to now using serial arithmetics (rfc1982).
  * That number of seconds is then converted to broken-out time information.
- * This is especially usefull when converting the inception and expiration
+ * This is especially useful when converting the inception and expiration
  * fields of RRSIG records.
  *
  * \param[in] time number of seconds since epoch (midnight, January 1st, 1970)
diff --git a/src/gldns/rrdef.h b/src/gldns/rrdef.h
index 3db78fe0..f7aaf866 100644
--- a/src/gldns/rrdef.h
+++ b/src/gldns/rrdef.h
@@ -332,13 +332,13 @@ enum gldns_enum_rdf_type
         GLDNS_RDF_TYPE_NSEC3_NEXT_OWNER,
 
         /** 4 shorts represented as 4 * 16 bit hex numbers
-         *  seperated by colons. For NID and L64.
+         *  separated by colons. For NID and L64.
          */
         GLDNS_RDF_TYPE_ILNP64,
 
-        /** 6 * 8 bit hex numbers seperated by dashes. For EUI48. */
+        /** 6 * 8 bit hex numbers separated by dashes. For EUI48. */
         GLDNS_RDF_TYPE_EUI48,
-        /** 8 * 8 bit hex numbers seperated by dashes. For EUI64. */
+        /** 8 * 8 bit hex numbers separated by dashes. For EUI64. */
         GLDNS_RDF_TYPE_EUI64,
 
         /** A non-zero sequence of US-ASCII letters and numbers in lower case.
diff --git a/src/mdns.c b/src/mdns.c
index 30bdab6e..34f95509 100644
--- a/src/mdns.c
+++ b/src/mdns.c
@@ -1638,7 +1638,7 @@ void _getdns_mdns_context_destroy(struct getdns_context *context)
 	}
 }
 
-/* TODO: actualy delete what is required.. */
+/* TODO: actually delete what is required.. */
 static void
 mdns_cleanup(getdns_network_req *netreq)
 {
diff --git a/src/mdns.h b/src/mdns.h
index 79ec05fe..aac5858f 100644
--- a/src/mdns.h
+++ b/src/mdns.h
@@ -59,7 +59,7 @@ typedef struct getdns_mdns_known_record
  * The data part contains:
  * - 64 bit time stamp
  * - 32 bit word describing the record size
- * - 32 bit word describing teh allocated memory size
+ * - 32 bit word describing the allocated memory size
  * - valid DNS response, including 1 query and N answers, 0 AUTH, 0 AD.
  * For economy, the names of all answers are encoded using header compression, pointing
  * to the name in the query, i.e. offset 12 from beginning of message.
diff --git a/src/request-internal.c b/src/request-internal.c
index 8b5dafdb..71110886 100644
--- a/src/request-internal.c
+++ b/src/request-internal.c
@@ -767,7 +767,7 @@ _getdns_dns_req_new(getdns_context *context, getdns_eventloop *loop,
 	      request_type == GETDNS_RRTYPE_AAAA );
 	/* Reserve for the buffer at least one more byte
 	 * (to test for udp overflow) (hence the + 1),
-	 * And align on the 8 byte boundry  (hence the (x + 7) / 8 * 8)
+	 * And align on the 8 byte boundary  (hence the (x + 7) / 8 * 8)
 	 */
 	size_t max_query_sz, max_response_sz, netreq_sz, dnsreq_base_sz;
 	uint8_t *region, *suffixes;
diff --git a/src/stub.c b/src/stub.c
index d24aa6fa..f1f5b278 100644
--- a/src/stub.c
+++ b/src/stub.c
@@ -112,7 +112,7 @@ rollover_secret()
 		return;
 
 	/* Remember previous secret, in to keep answering on rollover
-	 * boundry with old cookie.
+	 * boundary with old cookie.
 	 */
 	prev_secret = secret;
 	secret = arc4random();
@@ -899,7 +899,7 @@ tls_verify_callback(int preverify_ok, X509_STORE_CTX *ctx)
 			    "%-40s : Conn failed: TLS - *Failure* - Pinset validation failure\n",
 			    upstream->addr_str);
 	}
-	/* If nothing has failed yet and we had credentials, we have succesfully authenticated*/
+	/* If nothing has failed yet and we had credentials, we have successfully authenticated*/
 	if (preverify_ok == 0)
 		upstream->tls_auth_state = GETDNS_AUTH_FAILED;
 	else if (upstream->tls_auth_state == GETDNS_AUTH_NONE &&
@@ -1640,7 +1640,7 @@ stub_udp_write_cb(void *userarg)
 				  , STUB_DEBUG_WRITE, __FUNC__, (void *)netreq
 				  , _getdns_errnostr());
 		else
-			DEBUG_STUB( "%s %-35s: MSG: %p returned: %d, expeced: %d\n"
+			DEBUG_STUB( "%s %-35s: MSG: %p returned: %d, expected: %d\n"
 				  , STUB_DEBUG_WRITE, __FUNC__, (void *)netreq
 				  , (int)written, (int)pkt_len);
 #endif
@@ -1972,9 +1972,9 @@ upstream_valid(getdns_upstream *upstream,
                           getdns_network_req *netreq,
                           int backoff_ok)
 {
-	/* Checking upstreams with backoff_ok true will aslo return upstreams
+	/* Checking upstreams with backoff_ok true will also return upstreams
 	   that are in a backoff state. Otherwise only use upstreams that have
-	   a 'good' connection state. backoff_ok is usefull when no upstreams at all
+	   a 'good' connection state. backoff_ok is useful when no upstreams at all
 	   are valid, for example when the network connection is down and need to 
 	   keep trying to connect before failing completely. */
 	if (!(upstream->transport == transport && upstream_usable(upstream, backoff_ok)))
diff --git a/src/test/check_getdns_context_set_dns_transport.h b/src/test/check_getdns_context_set_dns_transport.h
index fbd7f503..ef847636 100644
--- a/src/test/check_getdns_context_set_dns_transport.h
+++ b/src/test/check_getdns_context_set_dns_transport.h
@@ -148,7 +148,7 @@
        getdns_bindata *version_str = NULL;
 
        /* Note that stricly this test just establishes that the requested transport
-          and the reported transport are consistent, it does not guarentee which
+          and the reported transport are consistent, it does not guarantee which
           transport is used on the wire...*/
 
        CONTEXT_CREATE(TRUE);
diff --git a/src/test/tpkg/270-header-extension.tpkg/270-header-extension.c b/src/test/tpkg/270-header-extension.tpkg/270-header-extension.c
index e845299b..8c344304 100644
--- a/src/test/tpkg/270-header-extension.tpkg/270-header-extension.c
+++ b/src/test/tpkg/270-header-extension.tpkg/270-header-extension.c
@@ -85,7 +85,7 @@ int main()
 		fprintf(stderr, "Could not do lookup");
 
 	else if ((r = getdns_dict_remove_name(response, "replies_full")))
-		fprintf(stderr, "Could not remove reponse['replies_full']");
+		fprintf(stderr, "Could not remove response['replies_full']");
 
 	else if ((r = getdns_dict_remove_name(response, "/replies_tree/0/header/id")))
 		fprintf(stderr, "Could not remove ID from response");
diff --git a/src/test/tpkg/run-one.sh b/src/test/tpkg/run-one.sh
index 10795374..4791cb4a 100755
--- a/src/test/tpkg/run-one.sh
+++ b/src/test/tpkg/run-one.sh
@@ -3,7 +3,7 @@
 export SRCDIR=`dirname $0`
 . `dirname $0`/setup-env.sh
 
-# pass a single test name as the first paramter (without .tpgk extension)
+# pass a single test name as the first parameter (without .tpgk extension)
 ONE_TEST=$1
 shift
 
diff --git a/src/test/tpkg/tpkg b/src/test/tpkg/tpkg
index 3701b723..6fc905bc 100755
--- a/src/test/tpkg/tpkg
+++ b/src/test/tpkg/tpkg
@@ -83,7 +83,7 @@ function write_result() {
 }
 
 function epoch() {
-        # make this sorta portable allthough not needed now
+        # make this sorta portable although not needed now
         epoch=0
         case $OSTYPE in
                 linux*)
@@ -819,7 +819,7 @@ done
 
 # this enhances the template from above
 ## Post Processing of some of these variables
-# dsc_aux is a comma seperated list of files, max 8 files
+# dsc_aux is a comma separated list of files, max 8 files
 i=$( echo $dsc_aux | awk -F', ?' '{ print $1 "\n" $2 "\n" $3 "\n" $4 "\n" \
 $5 "\n" $6 "\n" $7 "\n" $8 }' )
 dsc_aux_files=($i)
@@ -833,7 +833,7 @@ dsc_cmddepends_files_total=${#dsc_cmddepends_files[*]}
 for i in ${dsc_cmddepends_files[*]}; do
         find_cmd $i
 done
-# depends can also be a comma seperated list of package
+# depends can also be a comma separated list of package
 # TODO 
 
 # check is the aux files are also really in the shar
diff --git a/src/tools/getdns_server_mon.c b/src/tools/getdns_server_mon.c
index 93970f7f..c5aa6741 100644
--- a/src/tools/getdns_server_mon.c
+++ b/src/tools/getdns_server_mon.c
@@ -715,7 +715,7 @@ static exit_value get_report_info(struct test_info_s *test_info,
                                            "expire=%s;",
                                            buf);
                         } else {
-                                printf("Certicate expires:\t%s UTC\n", buf);
+                                printf("Certificate expires:\t%s UTC\n", buf);
                         }
                 }
         }
@@ -1407,7 +1407,7 @@ static exit_value test_dnssec_validate(struct test_info_s *test_info,
 
         /*
          * Only now get report info from the first search, so that any
-         * verbose output appears after the context/reponse dumps.
+         * verbose output appears after the context/response dumps.
          */
         if ((xit = get_report_info(test_info, response, NULL, NULL, NULL)) != EXIT_OK)
                 return xit;
diff --git a/src/types-internal.h b/src/types-internal.h
index 76615625..b683ca67 100644
--- a/src/types-internal.h
+++ b/src/types-internal.h
@@ -246,7 +246,7 @@ typedef struct getdns_network_req
 	size_t                  debug_udp;
 
 	/* When more space is needed for the wire_data response than is
-	 * available in wire_data[], it will be allocated seperately.
+	 * available in wire_data[], it will be allocated separately.
 	 * response will then not point to wire_data anymore.
 	 */
 	uint8_t *query;
@@ -380,8 +380,8 @@ typedef struct getdns_dns_req {
 	 *
 	 * Memory for these netreqs has been allocated by the same malloc
 	 * operation that reserved space for this getdns_dns_req.
-	 * They will thus be freed as part of the desctruction of this struct,
-	 * and do not need to be freed seperately.
+	 * They will thus be freed as part of the destruction of this struct,
+	 * and do not need to be freed separately.
 	 */
 	getdns_network_req *netreqs[];